Question on Connecting to DVI video for Sony SDM-M81 LCD.

This is an embarassing moment, when I've misplaced my manual and accessory cables for my Sony SDM-M81 LCD monitor. Maybe someone who owns one can help, the Sony site only addresses current models (this one is about 18 months old).I'm currently connected to the analogue video out of a Ge3 video card, through a cable that has the standard blue connector at the card end, and a similarly sized connector at the LCD end. The socket to the LCD is labelled "DVI-I", with a switch between digital and analogue. A second HD-15 input is analogue only (not connected).I'd like to use the digital video out of the video card, there's a small round connector on the card that is the digital out. Can anyone who owns one of these LCD's and has done this, help me with what cable is used to access the digital signal. Obviously it must have the same connector on the LCD as I'm using for analogue, as the one connector does for both standards. Is this a standard cable that I could purchase?Thanks for any information.Bruce.