Add SetStyle Function

wdgt_form.go

@@ -146,7 +146,8 @@ func (w *Form) Draw(screen tcell.Screen) {
 	}
 }
 
-func (w *Form) Active() bool { return w.active }
+func (w *Form) SetStyle(s tcell.Style) { w.style = s }
+func (w *Form) Active() bool           { return w.active }
 func (w *Form) SetActive(a bool) {
 	w.active = a
 	w.updateWidgets()