Oh Dear 
;
Checked my webpage in firefox and used the 'developer' toolbar 'Validate local HTML', I got 34 errors; How do I fix : I thought I'd do it now on my first page and thank-god I did, Imagine after a few pages confused:
A lot of the errors are showing <li> as this part that is invalid, but when I've been reading from w3schools.com and they said that this is how it should be written:<li>list</li>
I checked in safari and my horizontal list (navbar) does not centre correctly, I positioned each item as 150px wide seeing as though the container is 900. Ideally they would be flush each side with the ruler and spaced easily.
;Checked my webpage in firefox and used the 'developer' toolbar 'Validate local HTML', I got 34 errors
; How do I fix : I thought I'd do it now on my first page and thank-god I did, Imagine after a few pages confused:
HTML:
Validation Output: 34 Errors
1. Error Line 3, Column 1: Missing xmlns attribute for element html. The value should be: http://www.w3.org/1999/xhtml
<html>
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Many Document Types based on XML need a mandatory xmlns="" on the root element. For example, the root element for XHTML will look like:
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
2. Error Line 5, Column 74: end tag for "link" omitted, but OMITTAG NO was specified
type='text/css' href='layout2.cs
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You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
3. Info Line 5: start tag was here
><link rel='stylesheet' media="screen" type='text/css' href='layout2.css'>
4. Error Line 7, Column 7: end tag for "head" which is not finished
</head>
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Most likely, you nested tags and closed them in the wrong order. For example <p><em>...</p> is not acceptable, as <em> must be closed before <p>. Acceptable nesting is: <p><em>...</em></p>
Another possibility is that you used an element which requires a child element that you did not include. Hence the parent element is "not finished", not complete. For instance, in HTML the <head> element must contain a <title> child element, lists (ul, ol, dl) require list items (li, or dt, dd), and so on.
5. Warning Line 31, Column 125: cannot generate system identifier for general entity "kind"
albumid/5352451384466625153?alt=rss&kind=photo&hl=en_GB";
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An entity reference was found in the document, but there is no reference by that name defined. Often this is caused by misspelling the reference name, unencoded ampersands, or by leaving off the trailing semicolon (;). The most common cause of this error is unencoded ampersands in URLs as described by the WDG in "Ampersands in URLs".
Entity references start with an ampersand (&) and end with a semicolon (;). If you want to use a literal ampersand in your document you must encode it as "&" (even inside URLs!). Be careful to end entity references with a semicolon or your entity reference may get interpreted in connection with the following text. Also keep in mind that named entity references are case-sensitive; &Aelig; and æ are different characters.
If this error appears in some markup generated by PHP's session handling code, this article has explanations and solutions to your problem.
Note that in most documents, errors related to entity references will trigger up to 5 separate messages from the Validator. Usually these will all disappear when the original problem is fixed.
6. Error Line 31, Column 125: general entity "kind" not defined and no default entity
albumid/5352451384466625153?alt=rss&kind=photo&hl=en_GB";
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This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
7. Warning Line 31, Column 129: reference not terminated by REFC delimiter
mid/5352451384466625153?alt=rss&kind=photo&hl=en_GB";
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If you meant to include an entity that starts with "&", then you should terminate it with ";". Another reason for this error message is that you inadvertently created an entity by failing to escape an "&" character just before this text.
8. Error Line 31, Column 129: reference to entity "kind" for which no system identifier could be generated
mid/5352451384466625153?alt=rss&kind=photo&hl=en_GB";
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This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
9. Info Line 31, Column 123: entity was defined here
d/albumid/5352451384466625153?alt=rss&kind=photo&hl=en_GB";
10. Warning Line 31, Column 136: cannot generate system identifier for general entity "hl"
2451384466625153?alt=rss&kind=photo&hl=en_GB";
✉
An entity reference was found in the document, but there is no reference by that name defined. Often this is caused by misspelling the reference name, unencoded ampersands, or by leaving off the trailing semicolon (;). The most common cause of this error is unencoded ampersands in URLs as described by the WDG in "Ampersands in URLs".
Entity references start with an ampersand (&) and end with a semicolon (;). If you want to use a literal ampersand in your document you must encode it as "&" (even inside URLs!). Be careful to end entity references with a semicolon or your entity reference may get interpreted in connection with the following text. Also keep in mind that named entity references are case-sensitive; &Aelig; and æ are different characters.
If this error appears in some markup generated by PHP's session handling code, this article has explanations and solutions to your problem.
Note that in most documents, errors related to entity references will trigger up to 5 separate messages from the Validator. Usually these will all disappear when the original problem is fixed.
11. Error Line 31, Column 136: general entity "hl" not defined and no default entity
2451384466625153?alt=rss&kind=photo&hl=en_GB";
✉
This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
12. Warning Line 31, Column 138: reference not terminated by REFC delimiter
51384466625153?alt=rss&kind=photo&hl=en_GB";
✉
If you meant to include an entity that starts with "&", then you should terminate it with ";". Another reason for this error message is that you inadvertently created an entity by failing to escape an "&" character just before this text.
13. Error Line 31, Column 138: reference to entity "hl" for which no system identifier could be generated
51384466625153?alt=rss&kind=photo&hl=en_GB";
✉
This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.
14. Info Line 31, Column 134: entity was defined here
352451384466625153?alt=rss&kind=photo&hl=en_GB";
15. Error Line 48, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>3 Flight Mirrored Concrete Staircase</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
16. Error Line 49, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Cast-in-situ Concrete Staircase</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
17. Error Line 50, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Concrete Staircase</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
18. Error Line 51, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>2 Flight Staircase</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
19. Error Line 52, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Waterproof Concrete Basements
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
20. Error Line 53, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Waterproof Concrete Basement</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
21. Error Line 54, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Caltite Basement</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
22. Error Line 55, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Concrete Structures
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
23. Error Line 56, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Angle Formwork</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
24. Error Line 57, Column 4: document type does not allow element "li" here; missing one of "ul", "ol" start-tag
<li>Heat-Efficient Roof</li>
✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
25. Error Line 58, Column 5: end tag for "li" omitted, but OMITTAG NO was specified
</ul>
✉
You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
26. Info Line 55: start tag was here
s<li>Concrete Structures
27. Error Line 58, Column 5: end tag for "li" omitted, but OMITTAG NO was specified
</ul>
✉
You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
28. Info Line 52: start tag was here
s<li>Waterproof Concrete Basements
29. Error Line 58, Column 5: end tag for "li" omitted, but OMITTAG NO was specified
</ul>
✉
You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
30. Info Line 47: start tag was here
s<li>RC Staircases
31. Warning Line 60, Column 20: unclosed start-tag requires SHORTTAG YES
<div class="spacer"</div>
✉
The construct <foo<bar> is valid in HTML (it is an example of the rather obscure Shorttags feature) but its use is not recommended. In most cases, this is a typo that you will want to fix. If you really want to use shorttags, be aware that they are not well implemented by browsers.
32. Error Line 7, Column 7: XML Parsing Error: Opening and ending tag mismatch: link line 5 and head
</head>
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33. Error Line 31, Column > 80: XML Parsing Error: EntityRef: expecting ';'
m/data/feed/base/user/preciseformworklimited/albumid/5352451384466625153?alt=
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34. Error Line 31, Column > 80: XML Parsing Error: EntityRef: expecting ';'
m/data/feed/base/user/preciseformworklimited/albumid/5352451384466625153?alt=
✉
35. Error Line 58, Column 5: XML Parsing Error: Opening and ending tag mismatch: li line 55 and ul
</ul>
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36. Error Line 59, Column 6: XML Parsing Error: Opening and ending tag mismatch: li line 52 and div
</div>
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37. Error Line 60, Column 19: XML Parsing Error: attributes construct error
<div class="spacer"</div>
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38. Error Line 60, Column 19: XML Parsing Error: Couldn't find end of Start Tag div line 60
<div class="spacer"</div>
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39. Error Line 60, Column 25: XML Parsing Error: Opening and ending tag mismatch: li line 47 and div
<div class="spacer"</div>
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40. Error Line 69, Column 6: XML Parsing Error: Opening and ending tag mismatch: ul line 46 and div
</div>
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41. Error Line 70, Column 7: XML Parsing Error: Opening and ending tag mismatch: div line 45 and body
</body>
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42. Error Line 71, Column 7: XML Parsing Error: Opening and ending tag mismatch: div line 14 and html
</html>
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43. Error Line 71, Column 7: XML Parsing Error: Premature end of data in tag body line 9
</html>
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44. Error Line 71, Column 7: XML Parsing Error: Premature end of data in tag head line 4
</html>
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45. Error Line 71, Column 7: XML Parsing Error: Premature end of data in tag html line 3
</html>A lot of the errors are showing <li> as this part that is invalid, but when I've been reading from w3schools.com and they said that this is how it should be written:<li>list</li>
I checked in safari and my horizontal list (navbar) does not centre correctly, I positioned each item as 150px wide seeing as though the container is 900. Ideally they would be flush each side with the ruler and spaced easily.
