This demo demonstrate the use of the GeoExtUX_ZoomTo widget, which consist in a popup that allow the user to recenters the map on a user defined coordinate.

You can either use it without any projection list or specify your own. In the former case, EPSG:4326 and EPSG:900913 are used. In the latter, each projection defined automatically loads the according proj4js file containing its definition.

Here's a couple of coordinates you can use to test the widget :