opening a file in web browser

 hello,
I Have a requirement where i need to open a file in a new  browser.im using the following code but it is displaying a dialog box which consists of 3 buttons open,save,cancel.when u click open button of the text file ,the file will be opened in notepad,if it is .doc file it will be opened in microsoft word.

             string filename="xyz.txt";
            Response.ContentType = "application/doc";
            Response.AppendHeader("Content-Disposition", "attachment; filename=" + filename);
            Response.TransmitFile(Server.MapPath("~/Uploads/" + filename));
            Response.End();

I don't want the di ...