function vldLicense($lic)
{
echo "called with lic: ". $lic . "<br>";
echo preg_match('[A-Za-z0-9]', $lic) . "<br>";

if (preg_match('[A-Za-z0-9]{4}-[A-Za-z0-9]{4}-[A-Za-z0-9]{4}-[A-Za-
z0-9]{4}', $lic) == 0) return false;
return true;
}

gives me:

called with lic: 64gd-kwey-t643-ytes
0
Warning: preg_match() [function.preg-match]: Unknown modifier '{'

Why the 0 in the simple match?
Why the unknown modifier in the complex match?

Thanks in advance
Jan