[PHP] ereg is failing on this simple test

[Manuel Ochoa]

Why is this test failing?
 
$data = "A Simple test.";
If (ereg("^[a-zA-Z0-9\s.\-_']+$", $data)) {
  echo "Valid text";
}
else {
  echo "Not valid text";
}
 
I'm running PHP 4.34 on a windows pc. This function is new to me, any help would be 
appreciated.