/*! Present a dialtone and collect a certain length extension. Returns 1 on valid extension entered, -1 on hangup, or 0 on invalid extension. Note that if 'collect' holds digits already, new digits will be appended, so be sure it's initialized properly */
/*! Present a dialtone and collect a certain length extension. Returns 1 on valid extension entered, -1 on hangup, or 0 on invalid extension. Note that if 'collect' holds digits already, new digits will be appended, so be sure it's initialized properly */