manually chaning language -like alt-shift combination

Hi all,

I have two questions:

1.     I want to add the ability to write in some languages but without using the combination of alt-shift keys, I want to create a button that will do it.

          so my question is how can I change the language?

2.     I want to create the undo button that will do the same operation as ctrl+z, my code is:

               IEditManager(_textArea.textFlow.interactionManager).undo();  //_textArea is TextArea

                it doesn't work.....

               I think the problem is because when I press on the button the textArea loses the focus, so how can I prevent the loss of the focus?

thanks,

Benny