```
string filePath1 = (sender as LinkButton).CommandArgument;
string filepath = ("D:\\RetailAgreement\\" + filePath1);
FileInfo myfile = new FileInfo(filepath);
if (filePath1 != "")
{
    Response.ClearContent();
    Response.AddHeader("Content-Disposition", "attachment; filename=" + myfile.Name);
    Response.AddHeader("Content-Length", myfile.Length.ToString());
    Response.ContentType = ReturnExtension(myfile.Extension.ToLower());
    Response.TransmitFile(myfile.FullName);
    Response.End();

}

```

I tried like this but it is not working ,
I don't know where i went wrong. I am using C#3.0