var testresults;

function checkemail()
{
    var str = document.getElementById('email_address').value;
    var filter = /^([a-zA-Z0-9_\.\-\+])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

    if (filter.test(str))
    {
        testresults = true;
    }
    else 
    {
        alert("Please input a valid email address!");
        testresults = false;
    }
    return (testresults);
    
}