To duplicate an existing control in a window or dialog box, select the Duplicate control button on the toolbar. Move the pointer over the control to be duplicated. Then left-click, hold and move the control to where you want it placed in the window or dialog box. As soon as you release the button, the appropriate styles dialog box appears for the duplicated control, allowing you to edit the styles, text and ID values.
To cancel the duplicate-control mode, re-select the Duplicate control button on the toolbar.