I fly on my daughter's pass. Several locations have been great at getting me a ZED when I couldn't get a ride on US. I just had an agent (and his supervisor) refuse to do a ZED for me because I am not the employee. My wife just used America West by calling their 800 number and flew from LAX to STL for $20. Are there other airlines that will sell you their own ZED or equivalent for Interline travel?

Any help would be greatly appreciated!! Thanks