PHP function to write a blank 1px gif

gif.php

function writeGif()
{
	header( 'Content-type:  image/gif' );

	header( 'Expires: Wed, 11 Nov 1998 11:11:11 GMT' );

	header( 'Cache-Control: no-cache' );

	header( 'Cache-Control: must-revalidate' );

	echo base64_decode('R0lGODlhAQABAIAAAP///////yH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==');

	exit;
}