Stage Captureing and Sumbiting it

So i would like to know if its possible to have stage capture(like a screen grab) i have a user generated game that allows them to design an image, but i also want to be able to allow them the submit their drawing after they are completed.

I need help in writing the code for the submit button(that captures the stage). And the second part how would i let them submit it?

Thanks for you help in advance.