Asterisk - Conference with incoming calls

I need a system like this: 1-) System will make conference call with callers. We wont call them, we will make conference with incoming calls. 2-) We will have a web page for control everything. We have 2 lists. 1st list wil show active callers and numbers in conference in list view. Second list will list active numbers in the conference. In callers list; each number will have 2 buttons: accept and reject. In conference list; each number will have "disconnect" button and this button will disconnect number from the conference. 3-) If we accept calls, call will move to conference. If we reject, call will hangup and will be removed from list. Thank you.