Error in Asp,net when Partial Keyword Missing

IN ASP.NET WHILE COMPILING WE FOUND FOLLOWING ERROR SOME TIME ..

BASICALLY IT OCCURRED WHEN WE CUT PASTE ALL SOURCE CODE

ERROR DESCRIPTION-

<pre lang="msil">Error 1 &#39;ASP.mapstream_aspx.GetTypeHashCode()&#39;: no suitable method found to override c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\mapserverviewer\873018e3\324f1da0\App_Web_hka7dgu6.0.cs
Error 2 &#39;ASP.mapstream_aspx.ProcessRequest(System.Web.HttpContext)&#39;: no suitable method found to override c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\mapserverviewer\873018e3\324f1da0\App_Web_hka7dgu6.0.cs
Error 3 &#39;ASP.mapstream_aspx&#39; does not implement interface member &#39;System.Web.IHttpHandler.IsReusable&#39; c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\mapserverviewer\873018e3\324f1da0\App_Web_hka7dgu6.0.cs</pre>

if you found error some thing like above then

1)first check out this in code behind file -

public class Classname: System.Web.UI.Page

2) replace it with -

public class partial Classname: System.Web.UI.Page

your Problem should Solved..
-abid