The sysinfo command 'diskavailable' works perfectly when my External HDD is connected, but when they are disconnected they go crazy and show 8-10 digit number values.. I want them to say 0 when they are disconnected.. Does anyone know how to do this?

Here's an example using drives located at X:\ and Y:\. Change them accordingly. You also should see the pattern to add more drives or change the text. '1000' can be changed to a higher number if for some reason you have more than 1000GB. :P The following is all one line.

thanks so much, i was thinking along the lines of if over 700 GB... dont show or whatever.. exactly what you did.