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When you create a new form from scratch, it has no controls other than the Submit and Cancel button. To make your form useful you must start by dragging in controls from the Palette and dropping them in your form. As you begin to drag a control from the Palette, you’ll see this 
icon, which means the control is not yet over a droppable area. When you reach an area on the canvas where dropping a control is allowed, the will change to this Image Modified icon. You must drop controls into the body of the form; you can’t drop them into the toolbar nor can they be dropped below the Submit and Cancel buttons.
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