Hi, I would get the coordinate from an openlayers map. When I open my page I would that when I click on a button, I have received the coordinate of top bottom left and the upper right.
 <html>
<head>
  <title>OpenLayers Example</title>
    <script src="http://openlayers.org/api/OpenLayers.js"></script>
    </head>
    <body>
      <div style="width:100%; height:100%" id="map"></div>
      <script defer="defer" type="text/javascript">
        var map = new OpenLayers.Map('map');
        var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS",
            "http://labs.metacarta.com/wms/vmap0", {layers: 'basic'} );
        map.addLayer(wms);
        map.zoomToMaxExtent();
      </script>
<input type="button" text="Get Coordinate from map">
</body>
</html>
Thanks a lot.