[VBScript]
Property ContentType As String (read/write) 

Sets or returns the generated spreadsheet's MIME content type. In most browsers, Microsoft Excel files are mapped to the MIME type "application/vnd.ms-excel" and ExcelWriter's ContentType is set to this value by default. However, some browsers map Excel files to a different MIME content type, and the browser will not open a file of type "application/vnd.ms-Excel." In this case, set ContentType to the appropriate MIME content type.

In Internet Explorer, to find out what MIME content type maps to Excel files:

1. Open the Start menu and select Run.
2. Entire regedit to open the Registry Editor.
3. Open HKEY_CLASSES_ROOT\MIME\Database\Content Type. This folder contains a list of MIME content type folders. If you select a folder, you will see the extensions to which the type maps in the right frame.

In Netscape Navigator, to find out what MIME content type maps to Excel files:

1. In the browser window, open the Edit menu and select Preferences...
2. In the Category window select Applications.
3. In the Description window, select an application to display its MIME content type.

[VBScript]
Set xlw = CreateObject("Softartisans.ExcelWriter")
Set ws = xlw.Worksheets(1)
Set cells = ws.cells
cells.Cell("A1") = "Default content type is '" + xlw.ContentType + "'"
xlw.ContentType = "application/unknown"
cells.Cell("A2") = "New content type is set to '" + xlw.ContentType + "'"
xlw.Save "file.xls", saOpenInPlace