how to show word,rtf,pdf file in
plz give me code
thnks in advance

Use hyperlink.

<a href="file.pdf">PDF</a>

At first, read a document as a byte array. Use Response to show the document:
Here is the example of excel shown, for other document formats change ContentType.

// XLS
// Save Excel Workbook (XLS) to MemoryStream
byte[] bytes = wbook.WriteXLS().ToArray();
// Show Excel (XLS) in Browser window without saving on disk
Response.ContentType = "application/";