VBA script for mass changing data sources of layers within a .mxd

Hi,

I am a user of ArcGIS 9.3.1.

The "Setting Data Source" function in ArcCatalog to bulk change my layers in an .mxd does not work well. Only some of the layers are switched but others remained connected to the old data source. There are about a hundred layers in the .mxd so changing them manually every time is out of the question.

Does anyone have a customised VBA script that can perform the same task but more efficiently? I am not familiar with VBA so any assistance will be greatly appreciated.

Thanks!

Regards,
Siyang