Error in Site Validation

Does anyone know what this error is and how to fix it?

This is a css/html website. This error seems to pop up a lot.

Error Line 357, Column 7: XML Parsing Error: Premature end of data in tag body line 23.

</html>

without seeing the site code it is pretty difficult to debug that

does the site function just fine anyway

It seems to be fine. I just don't have the capability to check it on every browser, so I try to fix all the bugs.

Post the block of code that contains that line (and highlight the line in question) so I can have a look for you.

Yes, without having a look at the code, its' difficult to tell what it might be.