what is wrong with this code?

function formatPhoneNumber($phoneNumber) {

$phoneNumber = preg_replace('/[^0-9]/','',$phoneNumber);

if(strlen($phoneNumber) > 10) {

$countryCode = substr($phoneNumber, 0, strlen($phoneNumber)-10);

$areaCode = substr($phoneNumber, -10, 3);

$nextThree = substr($phoneNumber, -7, 3);

$lastFour = substr($phoneNumber, -4, 4);

$phoneNumber = '+'.$countryCode.' ('.$areaCode.') '.$nextThree.'-'.$lastFour;

}

else if(strlen($phoneNumber) == 10) {

$areaCode = substr($phoneNumber, 0, 3);

$nextThree = substr($phoneNumber, 3, 3);

$lastFour = substr($phoneNumber, 6, 4);

$phoneNumber = '('.$areaCode.') '.$nextThree.'-'.$lastFour;

}

else if(strlen($phoneNumber) == 7) {

$nextThree = substr($phoneNumber, 0, 3);

$lastFour = substr($phoneNumber, 3, 4);

$phoneNumber = $nextThree.'-'.$lastFour;

}

return $phoneNumber;

}

For some reason I get the number back as it was ie.12345467890 instead of (123)456-7890

Any help is appreciated

Mr A