var ns4 = (document.layers) ? true:false;		// Netscape 4.x
var ie = (document.all) ? true:false;			// IE version
var DOM = (document.getElementById) ? true:false;	// DOM supporting versions
var loaded = false;
function init(){	
	if (document.images){		
		images_off  = new Object();
  		images_on   = new Object();
		
		for( var x = 0; x < image_names.length; x++ ) {			
		images_off[image_names[x]] = new Image();
       	images_off[image_names[x]].src = "images/" + image_names[x] + ".jpg";
       	images_on[image_names[x]] = new Image();
       	images_on[image_names[x]].src = "images/" + image_names[x] + "_on.jpg";
		}			
	}
	loaded = true;			
}		
function rollOn(name) {
    if (loaded) {
		if (ns4) {
			s = document.images[name]; 
    		s.src = images_on[name].src;
    	}
    	else { document.images[name].src = images_on[name].src; }		
	}
}
function rollOff(name) {
    if(loaded) {
    	if(ns4) {
    		s = document.images[name]; 
    		s.src = images_off[name].src;
        }
    	else { document.images[name].src = images_off[name].src; } 		
    }
}

function openWindow(url,w,h){		
	xLoc = (screen.width/2) - w/2;	
	yLoc = 40
	if (screen.height <= 800){h=460}
	//alert(w + " " + h +" " + xLoc + " " +yLoc+" " +screen.width+" " +screen.height)
	popup=open(url,'popWindow','toolbar=1,resizable=1,menubar=1,location=1,status=1,scrollbars=1,Width='+w+',Height='+h+',screenX='+xLoc+',screenY='+yLoc+',left='+xLoc+',top='+yLoc)
	popup.focus();
}