// bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )
$a = array(array('c', 'd'), array('o', 'x'), 'y');
if (in_array(array('c', 'd'), $a))
echo "'c,d' array exist <br />";
if (in_array(array('o', 'x'), $a))
echo "'o,x' array exist <br />";
if (in_array('y', $a))
echo "'y' string exist <br />";
/*
run:
'c,d' array exist
'o,x' array exist
'y' string exist
*/