error in RUN the embedded function in simulink

Hi everybody

I am working on the the Matlab function in simulink I insert a simple function into embedded function the output of the function connected to the scope, when the run this massage will be displayed :

"Unable to locate a C-compiler required by Stateflow and MATLAB Function blocks. Use 'mex -setup' to select a supported C-compiler."

after this massage in the matlab comment I trying to determine default complier c (Microsoft visual c++ 2012 ) with mex –setup , but this compiler didn’t installed ,I download and install Microsoft Visual studio 2012 and SDK 2012 and visual C++ 2012. I determine the c compiler. BUT this massage exist yet !!!