Button On Click event not firing

the on click event works in other pages though.
here's the header of the page i'm trying to get it to work:
<%@ Page Title="Report" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Report.aspx.cs" Inherits="Report" %> <%@ PreviousPageType VirtualPath="~/Default.aspx">
when i click on it, it just redirects me to the PreviousPage. it also doesn't stop even when it has a breakpoint inside.
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