/************
// Bild                 : { Objektdaten }
"bild-2" :                {
                                url: 'Bild2.png', 
                                imageSize: [722, 154],
                                projection: proj,
                                imageExtent: proj.getExtent() 
                          }
*************/
                                
var bilder_switched = {
        "bild-switch_2" : {
                url: 'Bild2.png', 
                imageSize: [722, 154],
                projection: proj,
                imageExtent: proj.getExtent() 
                },
        "bild-switch_1" : {
                url: 'Bild1.png', 
                imageSize: [122, 44],
                projection: proj,
                imageExtent: proj.getExtent()
                }       
};


function switchChecked {
        for key in (bilder_switched) {
                if(document.getElementById(key).checked){
                        newL = new ol.layer.Image(bilder_switched[key]);
                        map.removeLayer(baseLayer);
                        map.addLayer(newL);
                }
        }
}