page cannot be found

I just downloaded FCKEditor.Net_2.6.3 and I copied the FredCK.FCKeditorV2.dll file to the bin folder and put this code in my .aspx page:
<FCKeditorV2:FCKeditor ID="FCKeditor1" runat="server" ></FCKeditorV2:FCKeditor>

when i run it, it gives me an error page cannot be found.

thanks for your help