function [kb,g_low,L,g_high,H]=dtmf_detectorB
L=[23,25,28,31];
H=[39,43,48,53];
load dtmf_data_B
g_low=abs(goertzel(HT(1:256),L)).^2;
[y_low,index_low]=max(g_low);
g_high=abs(goertzel(HT(1:256),H)).^2;
[y_high,index_high]=max(g_high);
key=['1','2','3','A';'4','5','6','B';'7','8','9','C';'*','0','#','D'];
kb=key(index_low,index_high);