function validateForm(oForm) 
{
    for (i=0; i<oForm.elements.length; i++)
    { 
        var bShowAlert = false;
        var sItems = "The following required fields must be filled: \r\n";
        
        if (oForm.elements[i].getAttribute('required') && oForm.elements[i].value.length == 0)
        { 
            sItems += oForm.elements[i].getAttribute('name') + "\r\n";
            bShowAlert = true;
        }
        if (bShowAlert)
        {
            alert(sItems);
            return false;
        }
    } 
    return true;
}