To decode a data file, make sure you rename your data file to match the name of the corresponding .map file.
For example, if you want to decode the graphics.dat file from the PC version of Dungeon Master,
 - copy the graphics.dat from DM PC (english only) to the folder containing the VBScript and the .map files
 - rename it to "GRAPHICS.DAT DM PC v3.4 English" (the same name as the .map file, but without the extension)
 - run the following command line:
 	"DM, CSB & DM2 Data File Decoder v3.0.vbs" "GRAPHICS.DAT DM PC v3.4 English"
 	
Alternatively, you can drag and drop data files or map files on the VBScript directly from Windows Explorer.
Decoded files will be stored in a folder with the name of the decoded file.