The following link gives you info on the windows bitmap file format: http://astronomy.swin.edu.au/~pbourke/dataformats/bmp/
In the header, you might be able to store an identifier in the reserved1 and resrved2 fields. Also, if you increase the offset to the image data, you could possibly insert some sort of identifier inbetween the header and the data. To do all this, you will need to read/write binary files, but I believe there is an xtra that does this. Good luck, Kevan Dettelbach Lunny Communications [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
