can't do postback

Hi,

I am trying to add some functionality to a page I have inherited, but I am unable to do a postback on the page.  This is how the button appears when I view source :

    <input type="submit" name="ctl00$ContentBody$btnUpload" value="Upload" onclick="javascript:WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions(&quot;ctl00$ContentBody$btnUpload&quot;, &quot;&quot;, true, &quot;&quot;, &quot;&quot;, false, false))" id="ctl00_ContentBody_btnUpload" />

And this is how it looks in design mode :

    <asp:Button ID="btnUpload" runat="server" OnClick="UploadFile_Click" Text="Upload" />

Can anybody please help with this, I am tearing my hair out trying to figure out why I can't postback!
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