function validate_form (form)
{
    valid = true;

    var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
    var email = form.lead_email.value;

    if ( form.lead_name.value == "" )
    {
        alert ( "Please enter your name." );
        valid = false;
    }
    else if ( reg.test(email) == false )
    {
        alert ( "Please enter a valid email address." );
        valid = false;
    }
    else if ( form.lead_phone.value == "" )
    {
        alert ( "Please enter your phone number." );
        valid = false;
    }

    return valid;
}