function in() {
	$arr = func_get_args();
	$val = $arr[0];
	unset($arr[0]);
	return in_array($val, $arr);
}

if (in($myvar, 1,2,3,4,5)) {...};

if (@$project_status['request']['action'] == 'new' || @$project_status['request']['action'] == 'jump' || @$project_status['request']['action'] == 'move') { ... }

if (in(@$project_status['request']['action'], 'new', 'jump', 'move')) { ... }

function in() {
	$arr = func_get_args();
	$val = $arr[0];
	unset($arr[0]);
	if (is_array($arr[1]))
		if (isset($arr[2]) && $arr[2] == true)
			return array_key_exists($val, $arr[1]);
		else
			return in_array($val, $arr[1]);
	return in_array($val, $arr);
}

$a = array(1=>'a', 2=>'b', 3=>'c');
if (in('b', $a)) {...} # in_array
if (in(2, $a, true)) {...} # array_key_exists