browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);

if (((browserName == "Netscape") && (browserVer >= 3)) || ((browserName == "Microsoft Internet Explorer") && (browserVer >= 4))) useImages = "1";
else useImages = "0";

if (useImages == "1")
{
    link_1_on = new Image;
	link_1_on.src = "images/link_1_1.jpg";  

	link_1_off = new Image;
	link_1_off.src = "images/link_1.jpg";

	link_2_on = new Image;
	link_2_on.src = "images/link_2_1.jpg";  

	link_2_off = new Image;
	link_2_off.src = "images/link_2.jpg"; 
	
	link_3_on = new Image;
	link_3_on.src = "images/link_3_1.jpg";  

	link_3_off = new Image;
	link_3_off.src = "images/link_3.jpg";  
	
	link_4_on = new Image;
	link_4_on.src = "images/link_4_1.jpg";  

	link_4_off = new Image;
	link_4_off.src = "images/link_4.jpg"; 
	
	link_5_on = new Image;
	link_5_on.src = "images/link_5_1.jpg";  

	link_5_off = new Image;
	link_5_off.src = "images/link_5.jpg";
	
	link_6_on = new Image;
	link_6_on.src = "images/link_6_1.jpg";  

	link_6_off = new Image;
	link_6_off.src = "images/link_6.jpg";
}

function ButtonOn(buttonId)
{
	 if ((document.images) && (useImages == "1"))
	 {
  		imgOn = eval("link_" + buttonId + "_on.src");
 		document.images["link_" +buttonId].src = imgOn;
 	}
}

function ButtonOff(buttonId)
{
	 if ((document.images) && (useImages == "1"))
 	{
  		 imgOff = eval("link_" + buttonId + "_off.src");
   		document.images["link_" +buttonId].src = imgOff;
 	}
}