How to solve this xy error code?

I am using Matlab R2008a and I type this code:*

>> %mencari nilai PSD dari data suara Odontoceti (Spinner - 2.wav)
[y,fs]=wavread('Spinner - 2.wav');
[pyy,f]=PSD(xy,256,fs,hamming(256),128,'none');
ys = 10*log10(pyy);
figure(1)
plot (f,ys,'k.-')
grid no
xlabel ('Frekuensi (Hz)')
ylabel ('PSD (dB/Hz)')
title ('Spinner 2')

but i got an error code like this:

??? Undefined function or variable 'xy'.

please help me how to solve this. thankyou

[madhan ravi]

Upload .wav file by clicking the paper clip button

[Anggit Raudina]

upload to where?

Answer 1

[Walter Roberson]

After

[y,fs]=wavread('Spinner - 2.wav');

Add

xy = y(:, 1);

[Anggit Raudina]

I've do it but I got another error code:

??? Error using ==> wavread at 67
Cannot open file.

and the number 67 is

      error('wavread:InvalidFile', msg);

[Walter Roberson]

Please show the output of

D = dir('*.wav');
N = {D.name};
N{:}