Link button and gridview button not firing onclick and clik

Question

One of my ASP page have some crazy issues.One of my asp page MeasurementNew.aspx/cs having this issues..Even break point doesn't come to that method (click event) i Didnt understand the problem

 

I attached my source code of thar particular class. please help me i didnt get whats happening 

these events are not working:
1.

Hide Copy Code

<asp:LinkButton ID="lbtnSRBook" runat="server" OnClick="lbtnSRBook_Click"           Style="font-weight: 700"                                             Text="Add Item"></asp:LinkButton> 

2."new item" button in gridview :gvDetail