getting error using header

[bulletz]

hello:
im trying to redirect to a certain browser using this one below:

headers ("location: URL");

but i get this error instead

Warning: Headers already sent by <points to php > .....

what seems to be the problem?

thanks

[Khalid Ali]

put the code at the very beginning of the page, that is the php code must come the first thing in the page,then doctype declarationif any and then html tag and the rest of the page