Email Validation using Php and Javascript

This function checks whether the email provided is valid and returns false if not valid.
Php Function for validating email
//$email -> email value to be validated.
function callEmailCheck($email, $strict = false)
{
    $regex = $strict? '/^([.0-9a-z_-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,4})$/i' : '/^([*+!.&#$¦\'\\%\/0-9a-z^_`{}=?~:-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,4})$/i' ;
    if (preg_match($regex, trim($email), $matches))    {
       return array($matches[1], $matches[2]);
    }
    else {
       return false;
    }
}
This function checks whether the user email entered in the text box is valid or not. Call this function on submit.
Javascript Function for validating email
function callEmailCheck() {


var emailreg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
//useremail is the name of the email text field.
var email = document.getElementById("useremail").value;
if(emailreg.test(email) == true){
return email;
}
return "";

}