hi.... i have a panasonic tda 100 hybrid p-pbx ...got a couple programming ?s on how to change some settings ...have a outline and inside line ...so on inside line if i dial an extension user and its busy ..have a busy tone/signal...i press 6 ...get a call back ring when that extension is open...with outside line i press 0 to get out ...but if its busy i get a phone off the hook tone .. no busy signal....no chance to press 6 for call back ... any ways to change that ?...also im on a 10 minute timer ...any ideas where to change that ...thanks