Mine

unction myScaleChanged( eventID, scale ) {
			    //todo: update scale select and enable/disable zoomin/zoomout
			    /*var oSelect = document.forms[0].scales;
			    for (var i=0; i<oSelect.options.length; i++)
			    {
			        if (oSelect.options[i].value == scale)
			        {
			            oSelect.options[i].selected = true;
			            document.getElementById("zoomOutButton").disabled = (i==0);
			            document.getElementById("zoomInButton").disabled = (i==oSelect.options.length - 1);
			            document.getElementById("zoomOutButton").className = (i==0) ? "disabled" : null;
			            document.getElementById("zoomInButton").className = (i==oSelect.options.length -1) ? "disabled" : null;
			        }
			    }*/
			    var currentMap = myKaMap.getCurrentMap();
			    this.scales = currentMap.getScales();
			    for(var i=0; i<this.scales.length; i++) {
			    	if(this.scales[i] == scale) {
			            document.getElementById("zoomOutButton").disabled = (i==0);
			            document.getElementById("zoomInButton").disabled = (i==this.scales.length - 1);
			            document.getElementById("zoomOutButton").className = (i==0) ? "disabled" : null;
			            document.getElementById("zoomInButton").className = (i==this.scales.length -1) ? "disabled" : null;
			    	}
			    }
			}