iOS Regular Expression problem grabbing data from html page

I have downloaded the RegexKitLite program to use for Regular Expressions.

What I need to do is capture from a web page all the data between the first instance of a div with its class as definition.

<div class='definition'> capture data between these tags </div>

I've solved the problem of how to get the web page loaded into a string but cannot figure out the correct regular expression. I use the regular expression
(?<=<div class='definition'>).*?(?=</div>). This works when I test it on a test string in the program such as :-

NSString *test = @"gfhfghfg<div class='definition'>test5678</div>llkklkkl";
NSLog(@"Match: %@", [test stringByMatching:regex capture:0]);

Result is :- Match: test5678

When I use it on the web page it doesn't work for some reason:-

NSData *response = [NSURLConnection sendSynchronousRequest: theRequest returningResponse: &resp error: &err];
NSString * theString = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

NSString* regex = @"<div class='definition'>(.*?)</div>";
NSLog(@"Match: %@", [theString stringByMatching:regex capture:0]);

Result is :- Match(null)

However if I change regex = @"<div class='definition'>(.*?)"

Result is :- Match: <div class='definition'>

which is not much use!
Could it be a problem with the encoding it is converted to UTF8.

Is anyone an expert on regular expressions or had a similar problem.
Thanks.

Here's my code if you can fix it.

//NSString *FeedURL2=@"http://www.urbandictionary.com/iphone/search/random";
//NSString *WordToSearch = txtSearch.text;
NSString *WordToSearch = "dog";
NSString *msg = @"search?term=";

msg = [msg stringByAppendingString:WordToSearch];
NSString *URL = @"http://www.urbandictionary.com/iphone/";
NSString *FeedURL = [URL stringByAppendingString:msg];

NSURLRequest *theRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:FeedURL]];
NSURLResponse *resp = nil;
NSError *err = nil;
NSData *response = [NSURLConnection sendSynchronousRequest: theRequest returningResponse: &resp error: &err];
NSString *theString = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

if (theString != nil)
{

NSString* regex = @"(?<=<div class='definition'>).*?(?=</div>)";
//NSString *test = @"dsdsa<div class='definition'>test5678hgfgdcxz</div>fghfghhg<div class='definition'>222222</div>";
NSLog(@"Match: %@", [theString stringByMatching:regex capture:0]);
}