detect an odd or even number function

Is there a php function to detect an odd or an even number?

There is now (see below). Just use the modulus. Like

function is_even($a){
$even = True;
if ($a % 2 != '0'){
$even = False;
}
return $even;
}
// example
for ($i=0;$i<=1000;$i ++){
if (is_even($i){
echo $i . ' is an even number.<br />';
} else {
echo $i ' is an odd number.<br />';
}
}