function md5_file ( str_filename ) {	// Calculates the md5 hash of a given file
	// 
	// + original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	return md5(file_get_contents(str_filename));
}

md5_file('http://kevin.vanzonneveld.net/pj_test_supportfile_1.htm');