Susan,
 I had the same problem some time ago. I couldn't find a sliding keyboard
the right size. I went to a local hardware specialty store and bought a set
of sliding drawer glides and a piece of particle board and built it. It
actually works smoother than any of the keyboard sliders you can buy at the
office supply stores. You won't save any money by doing it this way, but you
can build it just the way you need it!
Good Luck,
Jay Merritt

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