OpenGL Visual C++ Code Stops Updating

Ok, so I write some basic OpenGL code on Visual C++ 2010, draw a few polygons and then change things around on the code, like changing some vertices, or adding a line or a few points. It works fine for some tries, the code will update and each new OpenGL window will produce the updated vertices, and then it will stop updating. No matter what changes I make to the code the output graphic gets stuck to a last built image. Why does this happen?


We will need to see the code.