// JScript File

function validate()
{
    var x=document.getElementById('TextBox4');
    var str=x.value;
    if(str==""||str==null)
    {
        alert("Please Enter Your Email Address");
        x.focus();
        return false;
    }
    else
    {
        var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
        if(reg.test(str) == false)
        {
            alert('Invalid Email Address');
            x.focus();
            return false;
        }
        else
        {
            return true;
        }
    }
   
}