1 button parking

First of info about my Cisco Spa504/8G
7.5.2b Firmware
Running on Asterisk 1.8

Line Key is = fnc=blf+sd+cp;sub=71@$PROXY;nme=Park
PSK = fnc=sd;ext=70@$PROXY;nme=Park

Keep Referee When REFER Failed: NO

Now my question is how do i turn this into 1 button parking. as it is right now when i receive a call and press my “Park” softkey that i had put in under psk2 i would have to press “xferLx” key again to actually park the call. I just want it so i only need to press “Park” and the phone automatically parks the call and hangs up no questions ask.
In short the phone goes — Ring > Pick up > press Park > then xferLx > endcall
I need it to be ------------------Ring > Pick up > press Park > endcall

funny thing to mention though is if I am the caller and I need to park the call, pressing the park softkey will park the call and end it just the way i want it to be except i also want this feature when im the receiver of the call.

thanks for your time.