diff --git a/windows/win.c b/windows/win.c
index e146e89..d9366e4 100644
--- a/windows/win.c
+++ b/windows/win.c
@@ -1406,8 +1406,12 @@
     		WARN( win,"GWW_ID: discards high bits of 0x%08x!\n",
                     wndPtr->wIDmenu);
     	return (WORD)wndPtr->wIDmenu;
-    case GWW_HWNDPARENT: return wndPtr->parent ?
-			wndPtr->parent->hwndSelf : wndPtr->owner->hwndSelf;
+    case GWW_HWNDPARENT: 
+    	return wndPtr->parent ?
+		wndPtr->parent->hwndSelf : (
+			wndPtr->owner ?
+			 wndPtr->owner->hwndSelf : 
+			 0);
     case GWW_HINSTANCE:  
     	if (HIWORD(wndPtr->hInstance))
     		WARN(win,"GWW_HINSTANCE: discards high bits of 0x%08x!\n",
@@ -1728,6 +1732,15 @@
     return IsWindow32( hwnd );
 }
 
+void WINAPI WIN16_IsWindow16( CONTEXT *context )
+{
+    WORD *stack = PTR_SEG_OFF_TO_LIN(SS_reg(context), SP_reg(context));
+    HWND16 hwnd = (HWND16)stack[2];
+
+    AX_reg(context) = IsWindow32( hwnd );
+    ES_reg(context) = USER_HeapSel;
+}
+
 
 /*******************************************************************
  *         IsWindow32   (USER32.348)