CGI and CSS question

Hello,
I am writing a Perl script using CGI and CSS for my home page. The out
put from the script looks good except the hover doesn't work when I
point my cursor on the clickable item.
I am using an external file to code the fonts and formats. Basically
the style *** is effective on the fonts but not on the hover. Could
someone please tell me how to make this work?

Thanks in advance,
Sri.

.