I am searching for way to achieve this glass like effect on a gl shape. I have found this code : 

http://en.wikibooks.org/wiki/GLSL_Programming/Unity/Curved_Glass

 but I don't know how to turn it to work in max.

Maybe it is possible to achieve this effect in gen but I can not imagine how.

I am searching for way to achieve this glass like effect on a gl shape. I have found this code : http://en.wikibooks.org/wiki/GLSL_Programming/Unity/Curved_Glass but I don't know how to turn it to work in max.

glass-like-effect

As that link as written, you will need to write a GLSL shader to make the visual. Then use jit.gl.shader to load your shader code and apply it as you would on to objects like jit.gl.gridshape.

Read and practice with the Jitter Tutorials that are part of Max Help. Of most importance are Tutorials 31-35 and 41.

Yes, I have read these. I also have found Your First Shader tutorial on this site, and one book for shaders in and jitter. The problem is that GLSL is difficult for me. I have tried to adapt this code for jit.gl.slab like in Your First Shader tutorial, but of course it does not work because I do not understand the code.