pdf export problem

[mvenkatesan]

Hi
I'm using this code for pdf export from datagrid
and c# web appl.

Response.Clear();
Response.AddHeader("content-disposition", "attachment;filename="+strFile.Name);
Response.AddHeader("content-length", strFile.Length.ToString());
Response.Buffer = true;
Response.ContentType = "application/vnd.pdf";
Response.Charset = "";
this.EnableViewState = false;
this.ClearControls(gridname);
dgdMRPOutput.RenderControl(objHtmlTextWriter);
Response.Write(objStringWriter.ToString());
Response.End();
it exported to pdf
but i couldn't open the file, it displayed following error
"adobe reader could not open that file' .............. and wasnt correctly decoded

Is any mistake my code?

Pl guide me
Thanks to all
Venky