//用来标识是否点击了确定按钮来引发的页面加载,yes表示是
        string flag = Request.Form["flag"];
        if (flag == "yes")
        {
            //获取提交的表单数据
            oldPass = Request.Form["txtoldpass"];
            newPass = Request.Form["txtrpass"];
            conPass = Request.Form["txttpass"];
            //判断非空输入
            if (oldPass == string.Empty)
            {
                messageError = "原始密码不能为空";
                return;
            }
            if (string.IsNullOrEmpty(newPass))
            {
                messageError = "新密码不能为空";
                return;
            }
            if (string.IsNullOrEmpty(conPass))
            {
                messageError = "确认密码不能为空";
                return;
            }
            //2次密码输入不一样
            if (newPass != conPass)
            {
                messageError = "2次密码输入不一致";
                return;
            }
            ChangePassword();

}

上面的代码在VS2005里能正确弹出错误提示，但发布到IIS上就不行了，请高手相助