change filename to lowercase

hi all,

i just found out the filename system in Linux is case sensitive:o

there are lots of links in my page come up with the first letter is Uppercase, because the link is of a variable value.

for example, the link of a product in the search result will beCategory: <A HREF="<?php echo $row[5]; ?>.php"> <?php echo $row[5]; ?></A>
how do i change it to a lowercase link?

thanks

strtolower($row[5])

thanks!!!