Cannot modify header information error........usage of header method.

Hi all, I am using header method to redirect to a certain page.my first question is 1."Is there any other alternative to this method." 2.I am getting the error by using this method. the error is "Cannot modify header information - headers already sent by". i have seen the php documentation for header method. where there is one user comment about this. i have followed his steps like removing blank lines, using exit method. But the 3rd point that is "HTML goes before any PHP code ", i could not follow it , can some one please explain it. Thanks babu --------------------------------- Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with voicemail