Intercept outgoing call in Blackberry

Question

hi,

we are looking for a way to do the following:

• user with BB enters a number (or selects a contact and clicks 'send')
• our app in the background detects the call event
• our app does something (e.g. blocks the call / makes a call to a different number, etc)

can this be done at all? can it be done transparently to the user (i.e. no dialogs or user involvement)? which APIs should I look at?

Thanks