Example OpenLayers Map which uses WMS 1.3.0 GetMap requests.

WMS version 1.3.0 introduced the axis order sequence, so that for e.g. EPSG:4326 the bbox coordinate values need to be flipped (LatLon instead of LonLat). The map shows how to correctly request a map in EPSG:4326 against a WMS 1.3.0 service.