Micr0soft Dynamics CRM4.0 保存表单是的验证

if(IsNull(crmForm.all.new_nsrsbh)==false){


     var nsrsbh =crmForm.all.new_nsrsbh.DataValue;
     if(IsNull(nsrsbh)==false)
{
    return;
}
else
{
      alert("请输入纳税人识别号！");
      event.returnValue = false;
      return false;
}
}