mshtml: Added IHTMLEventObj::y implementation.

dlls/mshtml/htmlevent.c

@@ -646,10 +646,24 @@ static HRESULT WINAPI HTMLEventObj_get_x(IHTMLEventObj *iface, LONG *p)
 static HRESULT WINAPI HTMLEventObj_get_y(IHTMLEventObj *iface, LONG *p)
 {
     HTMLEventObj *This = impl_from_IHTMLEventObj(iface);
+    LONG y = 0;
 
-    FIXME("(%p)->(%p)\n", This, p);
+    TRACE("(%p)->(%p)\n", This, p);
+
+    if(This->nsevent) {
+        nsIDOMUIEvent *ui_event;
+        nsresult nsres;
 
-    *p = -1;
+        nsres = nsIDOMEvent_QueryInterface(This->nsevent, &IID_nsIDOMUIEvent, (void**)&ui_event);
+        if(NS_SUCCEEDED(nsres)) {
+            /* NOTE: pageY is not exactly right here. */
+            nsres = nsIDOMUIEvent_GetPageY(ui_event, &y);
+            assert(nsres == NS_OK);
+            nsIDOMUIEvent_Release(ui_event);
+        }
+    }
+
+    *p = y;
     return S_OK;
 }