var errorClass = "errorText";

function SetErrorClass(valId, ctrlId, parentId) {
    var validator = $("#" + valId)[0];
    if (validator == undefined)
        return true; // probably disabled

    var control = $("#" + ctrlId); // control to validate
    var parent = null; // optional parent control to check
    if (parentId != null && parentId != undefined) {
        parent = $('#' + parentId);
    }

    if (parent == null || (parent != null && !parent.hasClass('hidden')))
    {
        // force validation
        ValidatorValidate(validator);

        // set css-class
        if (validator.isvalid) {
            control.removeClass(errorClass);
        }
        else if (!validator.isvalid && !control.hasClass(errorClass)) {
            control.addClass(errorClass);
        }
        return validator.isvalid;
    }
}