i would like to use if statement from simulink to access the pixel information

I am using matlab simulink for my project work but i donot understand how to use if statement for accessing pixel information of any image. plz plz help me. and also i got following error whenever i am using matlab function. plz plz help me

 The current directory 'c:\program files\matlab\r2013a\bin' is reserved for MATLAB files.
 Please change your current directory to a writeable directory outside of the MATLAB installation area.

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/105063-what-should-i-have-to-overcome-the-error-of-please-change-your-current-directory-to-a-writable-direc