how can i figure my car alarm fob out?

i have bought a used car with a toad cat 1 alarm installed but have no idea how the fob works except the big black button opens the central locking and disarms the alarm and the big green button does the opposite. what do the smaller buttons do, also my wife opened the door with the key which activated the alarm and now the horn does'nt work!!! any ideas. thanks Roy.

Roy Higgins
April 2007