当我将IE浏览器模式从IE9切换到IE8时，为什么会出现“Page_Validators”没有定义的错误?

I am developing a web page using ASP.NET unobtrusive validation. When I view my page in IE9 using the default IE9 Browser Mode, the page works as expected. However, when I simply switch the Browser Mode from IE9 to IE8, I receive the following JavaScript error as the page reloads:I am developing a web page using ASP.NET unobtr