Added buttons.

1 files changed, 2 insertions, 1 deletions

diff --git a/sysdata.go b/sysdata.go
index 824df0c..1d4ecbd 100644
--- a/sysdata.go
+++ b/sysdata.go
@@ -7,7 +7,8 @@ import (
 
 // The sysData type contains all system data. It provides the system-specific underlying implementation. It is guaranteed to have the following by embedding:
 type cSysData struct {
-	ctype	int
+	ctype			int
+	parentWindow		*sysData
 
 	// for Window
 	closing	chan struct{}