hehe... this is an HTML question really but i will give you the answer because I am kind.
IF you need to use PHP simply use the echo() function as follows.
<?
echo "<meta http-equiv=\"refresh\" content=\"3;URL=http://www.php.net\">";
?>
The number 3 standing for 3 seconds and replace the http://www.php.net with the URL you need.
NOTE: This must be placed between the <head> and </head> of html page.
Thanks