How to record audio using MATLAB?

I tried to record audio using microphone using the following code.

 recObj=audiorecorder(8000,8,1);
 disp('Start speaking.')
 record(recObj,5);
 disp('End of Recording.');

But the problem is while I run the program,MATLAB stops working and closes the program.I am using MATLAB 7. I also looked for the documentation for my version thinking if recording is no compatible for my version.But it is compatible. Can anyone help me with it?