/*
			     * Create a Custom Opacity GControl
			     * http://www.maptiler.org/google-maps-overlay-opacity-control/
			     */

			    var CTransparencyLENGTH = 58; 
			    // maximum width that the knob can move (slide width minus knob width)
			    

			    
			       function CTransparencyControl( overlay ) {
			        this.overlay = overlay;
			        this.opacity = overlay.getTileLayer().getOpacity();
			    }
			    CTransparencyControl.prototype = new GControl();

			    // This function positions the slider to match the specified opacity
			    CTransparencyControl.prototype.setSlider = function(pos) {
			        var left = Math.round((CTransparencyLENGTH*pos));
			        this.slide.left = left;
			        this.knob.style.left = left+"px";
			        this.knob.style.top = "0px";
			    }

			    // This function reads the slider and sets the overlay opacity level
			    CTransparencyControl.prototype.setOpacity = function() {
				    // set the global variable
			        opacity = this.slide.left/CTransparencyLENGTH;
			       this.map.clearOverlays();
			  //     map.removeOverlay(hybridOverlay);
			  //		this.map.removeOverlay(hybridOverlay);
			        this.map.addOverlay(this.overlay, { zPriority: 0 });
			        if (this.map.getCurrentMapType() == G_HYBRID_MAP) {
			            this.map.addOverlay(hybridOverlay);
			        }
			    }

			    // This gets called by the API when addControl(new CTransparencyControl())
			    CTransparencyControl.prototype.initialize = function(map) {
			        var that=this;
			        this.map = map;

			        // Is this MSIE, if so we need to use AlphaImageLoader
			        var agent = navigator.userAgent.toLowerCase();
			        if ((agent.indexOf("msie") > -1) && (agent.indexOf("opera") < 1)){this.ie = true} else {this.ie = false}

			        // create the background graphic as a <div> containing an image
			        var container = document.createElement("div");
			        container.style.width="70px";
			        container.style.height="21px";

			        // Handle transparent PNG files in MSIE
			        if (this.ie) {
			          var loader = "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='http://www.maptiler.org/img/opacity-slider.png', sizingMethod='crop');";
			          container.innerHTML = '<div style="height:21px; width:70px; ' +loader+ '" ></div>';
			        } else {
			          container.innerHTML = '<div style="height:21px; width:70px; background-image: url(http://www.maptiler.org/img/opacity-slider.png)" ></div>';
			        }

			        // create the knob as a GDraggableObject
			        // Handle transparent PNG files in MSIE
			        if (this.ie) {
			          var loader = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='http://www.maptiler.org/img/opacity-slider.png', sizingMethod='crop');";
			          this.knob = document.createElement("div"); 
			          this.knob.style.height="21px";
			          this.knob.style.width="13px";
				  this.knob.style.overflow="hidden";
			          this.knob_img = document.createElement("div"); 
			          this.knob_img.style.height="21px";
			          this.knob_img.style.width="83px";
			          this.knob_img.style.filter=loader;
				  this.knob_img.style.position="relative";
				  this.knob_img.style.left="-70px";
			          this.knob.appendChild(this.knob_img);
			        } else {
			          this.knob = document.createElement("div"); 
			          this.knob.style.height="21px";
			          this.knob.style.width="13px";
			          this.knob.style.backgroundImage="url(http://www.maptiler.org/img/opacity-slider.png)";
			          this.knob.style.backgroundPosition="-70px 0px";
			        }
			        container.appendChild(this.knob);
			        this.slide=new GDraggableObject(this.knob, {container:container});
			        this.slide.setDraggableCursor('pointer');
			        this.slide.setDraggingCursor('pointer');
			        this.container = container;

			        // attach the control to the map
			        map.getContainer().appendChild(container);

			        // init slider
			        this.setSlider(this.opacity);

			        // Listen for the slider being moved and set the opacity
			        GEvent.addListener(this.slide, "dragend", function() {that.setOpacity()});
			        //GEvent.addListener(this.container, "click", function( x, y ) { alert(x, y) });

			        return container;
			      }

			      // Set the default position for the control
			      CTransparencyControl.prototype.getDefaultPosition = function() {
			        return new GControlPosition(G_ANCHOR_TOP_RIGHT, new GSize(7, 47));
			      }