Save option in right-click menu

Hello everyone.

I ve recently started to read about Context Menus, but i dont know how i can make a “save” command. Of course this has nothing to do with the context menu, but it would be nice if it was there. Can anyone tell me how can i make a save option so that a user would be able to save a picture (as if it was an html page) ? Does it require use of xml in order a “save as” window can be opened ?

Thanks.