function refreshMap() {
    var layeron = new Array();
    var layeroff = new Array();
    ioff = 0;
    ion = 0;
	if(document.layers.layername.length == null) { // cas d'un seul élément
		if(document.layers.layername.checked == true){
			if(document.layers.layername.value!='on') {
				layeron[ion] = document.layers.layername.value;
				ion++;
			}
		} else
			if(document.layers.layername.value!='on') {
				layeroff[ioff] = document.layers.layername.value;
				ioff++;
			}
	}
	else { // cas de plusieurs éléments
		for(i=0; i<document.layers.layername.length; i++) 
			if(document.layers.layername[i].checked == true){
				if(document.layers.layername[i].value!='on') {
					layeron[ion] = document.layers.layername[i].value;
					ion++;
				}
			} else
				if(document.layers.layername[i].value!='on') {
					layeroff[ioff] = document.layers.layername[i].value;
					ioff++;
				}
    }
    parent.processmap.doLayerVisibility('layers',layeroff,layeron);
}