Matlab :detect frequency of dtmf tone (.wav )file

[mohajernow]

a question in MATLAB ?
i have a DTMF tone as a ( .wav ) file and i want to detect
its frequency then i want to know the number which
the tone belong to

note i have a .wav file and i want to detect it


i am trying forrier then using "find function "in matlab
but the result of "find " have a lot of number
what i can do to solve this problem

here is my attempt

[y1,fs,n]=wavread('tone4.wav');
Ts=1/fs
y=fft(y1);
y=Ts*fftshift(y);
freq =find (y)

 

[mohajernow]

i found another way to know the frequency but i do not konw how to use it
the methode depend on finding the frequency which has the highest magnitude

i do not know how to get the highest magnitude