diff --git a/stdwndclass_windows.go b/stdwndclass_windows.go
index e6796e5..730cd51 100644
--- a/stdwndclass_windows.go
+++ b/stdwndclass_windows.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"syscall"
 	"unsafe"
+	"sync"
 )
 
 const (
@@ -16,8 +17,26 @@ var (
 )
 
 func stdWndProc(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
-	// TODO get CreateWindowEx data
+	sysData := getSysData(hwnd)
 	switch uMsg {
+	case _WM_COMMAND:
+		id := wParam.LOWORD()
+		// ... member events
+		_ = id
+		return 0
+	case _WM_GETMINMAXINFO:
+		mm := lParam.MINMAXINFO()
+		// ... minimum size
+		_ = mm
+		return 0
+	case _WM_SIZE:
+		// TODO
+		return 0
+	case _WM_CLOSE:
+		if sysData.closing != nil {
+			sysData.closing <- struct{}
+		}
+		return 0
 	default:
 		r1, _, _ := defWindowProc.Call(
 			uintptr(hwnd),
diff --git a/sysdata.go b/sysdata.go
index eb4d8ea..298c1ef 100644
--- a/sysdata.go
+++ b/sysdata.go
@@ -9,6 +9,9 @@ import (
 type cSysData struct {
 	ctype	int
 	text		string
+
+	// for Window
+	closing	chan struct{}
 }
 func (c *cSysData) make() error {
 	panic(runtime.GOOS + " sysData does not define make()")
diff --git a/sysdatacache_windows.go b/sysdatacache_windows.go
new file mode 100644
index 0000000..1a45d97
--- /dev/null
+++ b/sysdatacache_windows.go
@@ -0,0 +1,58 @@
+// 11 february 2014
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+// I need a way to get a sysData for a given HWND or a given HWND/control ID. So, this.
+
+type sdcEntry struct {
+	s			*sysData
+	members		map[_HMENU]*sysData
+}
+
+var (
+	sysDatas = map[_HWND]*sdcEntry{}
+	sysDatasLock sys.Mutex
+)
+
+func addSysData(hwnd _HWND, s *sysData) {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
+	sysDatas[hwnd] = &sdcEntry{
+		s:			s,
+		members:		map[_HMENU]*sysData{},
+	}
+}
+
+func addIDSysData(hwnd _HWND, id _HMENU, s *sysData) {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
+	if ss, ok := sysDatas[hwnd]; ok {
+		ss.members[id] = s
+	}
+	panic(fmt.Sprintf("adding ID %d to nonexistent HWND %d\n", id, hwnd))
+}
+
+func getSysData(hwnd _HWND) *sysData {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
+	if ss, ok := sysDatas[hwnd]; ok {
+		return ss.s
+	}
+	panic(fmt.Sprintf("getting nonexistent HWND %d\n", hwnd))
+}
+
+func getIDSysData(hwnd _HWND, id _HMENU) *sysData {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
+	if ss, ok := sysDatas[hwnd]; ok {
+		if xx, ok := ss.members[id]; ok {
+			return xx
+		}
+		panic(fmt.Sprintf("getting nonexistent ID %d for HWND %d\n", id, hwnd))
+	}
+	panic(fmt.Sprintf("getting nonexistent HWND %d\n", hwnd))
+}
diff --git a/window.go b/window.go
index 45ae9f3..c04d276 100644
--- a/window.go
+++ b/window.go
@@ -57,6 +57,7 @@ func (w *Window) Open() (err error) {
 
 	// If the window has already been created, show it.
 	if !w.created {
+		w.sysData.closing = w.Closing
 		err = w.sysData.make()
 		if err != nil {
 			return err
@@ -72,6 +73,7 @@ func (w *Window) Open() (err error) {
 }
 
 // Close closes the window. The window is not destroyed; it is merely hidden.
+// TODO don't send on w.Closing
 func (w *Window) Close() (err error) {
 	return w.sysData.hide()
 }