Web Forms :: LightBox Effect On Master And Content Page

I am developing a project which has a master page and content page.In my content page I was using a gridview query from database with image display as an image button, when user click on the image in the gridview it will trigged a lightbox through Javascript. I follow the tutorial from the link in the following link [URL]

Everything works great when its on a stand alone page , however, as soon as I put the GridView in my content page then click on the image from the image button in the GridView I will be resulting the following error. Server Error in '/Photo_Master' Application. Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page nableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Here is my code, I noticed OnClientClick = "return LoadDiv(this.src);" in the following image button will return false to prevent postback, however, it will only work if this is a stand alone page but not in the content page that links to a master page. I had tried the following approaches, but none of them works.

1.) EnableEventValidation = "false" --- Page is not going to break at least but No Lightbox pop up.

2.) Added PostBackURL ="javascript:Void(0);" as the properties of <asp:imagebutton> in the GridView - Did not work.

*PS - I had tried to put my lightbox pop up page on either master or content page tried different ways , however, nothing works. My goal is to have the PhotoGallery display in GridView where image display as an ASP.net imagebutton control under the content page, when user click on the imagebutton the lightbox effect will show.

[Code]....