Set Background image of MDI form as back color of label

I am developing a windows app using C#. I have a MDI Parent form and a label on it. I have set the background image of Mdi parent through code and now I want that the label should be transparent but it doesn't become.

How can I set the background image of Mdi form as back color of label control or any other control...??

 

How can I do this...???

 

Thanks in Advance.....!!!