function entsub(event, myform) {

        var keynum;

        if(window.event) // IE
        {
            keynum = event.keyCode;
        }
        else if(event.which) // Netscape/Firefox/Opera
        {
            keynum = event.which;
        }
          
        if (keynum == 13) {
            myform.submit();
        }
    }