function checkEnter(e)
{
    var characterCode;
    if (e && e.which)
    {
        characterCode = e.which;
    }
    else
    {
        e = event;
        characterCode = e.keyCode;
    }

    if (characterCode == 13)
    {
        document.forms[0].submit();
        return (false);
    }
    return (true);
}