TextEdit

All of a sudden, when I tried to save a Textedit document to the desktop, I received the following message:
" The document “Untitled” could not be saved as “xx.rtf”. You don’t have permission.
To view or change permissions, select the item in the Finder and choose File > Get Info."
I cannot find "Get Info" under the TextEdit file icon.
iMac 10.8.4.
I tried BEAN with the same result. I can save in PAGES.
What can I do? Thanks.

Renaming file .......

...... doesn't work either. Yes I can create a new folder, but that's not the problem. I can't save the file to any folder.