diff --git a/redo/controls.go b/redo/controls.go
index 3fb2a54..6de193a 100644
--- a/redo/controls.go
+++ b/redo/controls.go
@@ -25,6 +25,6 @@ type Button interface {
 }
 
 // NewButton creates a new Button with the given label text.
-func NewButton(text string) {
+func NewButton(text string) *button {
 	return newButton(text)
 }
diff --git a/redo/controls_windows.go b/redo/controls_windows.go
index 81ad2ac..84b5625 100644
--- a/redo/controls_windows.go
+++ b/redo/controls_windows.go
@@ -47,7 +47,6 @@ type button struct {
 var buttonclass = toUTF16("BUTTON")
 
 func newButton(text string) *button {
-	op:		func() {
 	w := newWidget(buttonclass,
 		C.BS_PUSHBUTTON | C.WS_TABSTOP,
 		0)
@@ -70,7 +69,7 @@ func (b *button) Text() string {
 }
 
 func (b *button) SetText(text string) {
-	return b.settext(text)
+	b.settext(text)
 }
 
 //export buttonClicked
diff --git a/redo/uitask.go b/redo/uitask.go
index 8b5e523..43068e7 100644
--- a/redo/uitask.go
+++ b/redo/uitask.go
@@ -5,6 +5,7 @@ package ui
 import (
 	"runtime"
 	"sync"
+	"unsafe"
 )
 
 // Go initializes package ui.
@@ -42,7 +43,7 @@ func Stop() {
 
 type event struct {
 	// All events internally return bool; those that don't will be wrapped around to return a dummy value.
-	do		func(c Doer) bool
+	do		func() bool
 	lock		sync.Mutex
 }
 
@@ -50,31 +51,31 @@ type event struct {
 
 func newEvent() *event {
 	return &event{
-		do:	func(c Doer) bool {
+		do:	func() bool {
 			return false
 		},
 	}
 }
 
-func (e *event) set(f func(Doer)) {
+func (e *event) set(f func()) {
 	e.lock.Lock()
 	defer e.lock.Unlock()
 
 	if f == nil {
-		f = func(c Doer) {}
+		f = func() {}
 	}
-	e.do = func(c Doer) bool {
-		f(c)
+	e.do = func() bool {
+		f()
 		return false
 	}
 }
 
-func (e *event) setbool(f func(Doer) bool) {
+func (e *event) setbool(f func() bool) {
 	e.lock.Lock()
 	defer e.lock.Unlock()
 
 	if f == nil {
-		f = func(c Doer) bool {
+		f = func() bool {
 			return false
 		}
 	}
@@ -87,7 +88,7 @@ func (e *event) fire() bool {
 	e.lock.Lock()
 	defer e.lock.Unlock()
 
-	return e.do(c)
+	return e.do()
 }
 
 // Common code for performing a requested action (ui.Do() or ui.Stop()).
diff --git a/redo/zz_test.go b/redo/zz_test.go
index 50a4aee..a0751dc 100644
--- a/redo/zz_test.go
+++ b/redo/zz_test.go
@@ -15,14 +15,14 @@ var closeOnClick = flag.Bool("close", false, "close on click")
 func init() {
 	flag.Parse()
 	go Do(func() {
-		w := NewWindow(Do, "Hello", 320, 240)
-		b := NewButton(Do, "There")
+		w := NewWindow("Hello", 320, 240)
+		b := NewButton("There")
 		w.SetControl(b)
 		if *closeOnClick {
 			b.SetText("Click to Close")
 		}
 		done := make(chan struct{})
-		w.OnClosing(func(c Doer) bool {
+		w.OnClosing(func() bool {
 			if *closeOnClick {
 				panic("window closed normally in close on click mode (should not happen)")
 			}
@@ -31,17 +31,17 @@ func init() {
 			done <- struct{}{}
 			return true
 		})
-		b.OnClicked(func(c Doer) {
+		b.OnClicked(func() {
 			println("in OnClicked()")
 			if *closeOnClick {
-				Wait(c, w.Close())
+				w.Close()
 				Stop()
 				done <- struct{}{}
 			}
 		})
 		w.Show()
 		<-done
-	})()
+	})
 	err := Go()
 	if err != nil {
 		panic(err)