about data acquisition tool

i write a matlab code to take input though sound card. When i run this code i get 2 type of error in two different PC,s Please help me for this any one Code is this

AI=analoginput('winsound');
addchannel(AI,1);
Fs = 8000;
set(AI,'SampleRate',Fs)
duration = 2;
set(AI,'SamplesPerTrigger',duration*Fs);
start(AI);
data=getdata(AI);
delete(AI)
xfft = abs(fft(data));
mag = 20*log10(xfft);
mag = mag(1:end/2);
[ymax,maxindex]=max(mag);

When i Run this I get this error

Error
??? Error: "data" was previously used as a variable,
 conflicting with its use here as the name of a function or command.
 See MATLAB Programming, "How MATLAB Recognizes Function Calls That
 Use Command Syntax" for details.

This error in old pc and second error in new pc is this

??? Error using ==> playsnd
Frequency must be a scalar

Error in ==> sound at 58
playsnd(y,fs,bits);

[Walter Roberson]

The code you show us does not have any call to playsnd() . Perhaps your actual code is longer than this?