popup actually can use 'parentNode' to determine his parent. so no need to set anything. also, only try removing from viewPortDiv if popup.div is not null

git-svn-id: http://svn.openlayers.org/trunk/openlayers@231 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Map.js

@@ -151,7 +151,6 @@ OpenLayers.Map.prototype = {
     * @param {OpenLayers.Popup} popup
     */
     addPopup: function(popup) {
-        popup.parent = this.viewPortDiv;
         this.popups.push(popup);
         var popupDiv = popup.draw();
         if (popupDiv) {
@@ -166,9 +165,11 @@ OpenLayers.Map.prototype = {
     */
     removePopup: function(popup) {
         this.popups.remove(popup);
-        this.viewPortDiv.removeChild(popup.div);
+        if (popup.div) {
+            this.viewPortDiv.removeChild(popup.div);
+        }
     },
-    
+        
     /**
     * @return {float}
     */