problem getting rssi from xbee using mbed board

hey guys,
i m using two xbee S2 and 2 mbed boards… one mbed and xbee as a tx and same on the other side for rx

i need to calculate the rssi at the RX end

i used the code given at http://mbed.org/users/ATKINZ117/code/XBeeGetRSSISampleProgram/
but this isnt helping… i m getting 0dbm as a answer

can anyone help me with codes… both for tx and rx asap plz

can’t you just get it’s DB value?

This command reports the received signal strength of the
last received RF data packet. The DB command only indicates the signal strength of the
last hop. It does not provide an accurate quality measurement for a multihop link. DB can
be set to 0 to clear it. The DB command value is measured in -dBm. For example if DB
returns 0x50, then the RSSI of the last packet received was
-80dBm. As of 2x6x firmware, the DB command value is also updated when an APS
acknowledgment is received.