linking radio buttons and textboxs and buttons please help

Question

Design a simple calculator as shown in the form below. When the user clicks on any of the three radio buttons, the corresponding button (Add, Subtract or Multiply) should remain in display while the others are made invisible. When the user enters values into the textboxes and clicks on the button, the result should display in a message box while the textboxes are cleared at the same time.

 

 please help