if(document.images){

//top navigation on

var onImgs = new Array();
onImgs["home"] = new Image(59,18);
onImgs["home"].src = "../image/topnav/home_o.gif";
onImgs["search"] = new Image(135,18);
onImgs["search"].src = "../image/topnav/search_o.gif";
onImgs["demo"] = new Image(103,18);
onImgs["demo"].src = "../image/topnav/demo_o.gif";
onImgs["comp"] = new Image(141,18);
onImgs["comp"].src = "../image/topnav/comp_o.gif";
onImgs["clipdemand"] = new Image(130,18);
onImgs["clipdemand"].src = "../image/topnav/clipdemand_o.gif";
onImgs["help"] = new Image(58,18);
onImgs["help"].src = "../image/topnav/help_o.gif";


var offImgs = new Array();
offImgs["home"] = new Image(59,18);
offImgs["home"].src = "../image/topnav/home.gif";
offImgs["search"] = new Image(135,18);
offImgs["search"].src = "../image/topnav/search.gif";
offImgs["demo"] = new Image(103,18);
offImgs["demo"].src = "../image/topnav/demo.gif";
offImgs["comp"] = new Image(141,18);
offImgs["comp"].src = "../image/topnav/comp.gif";
offImgs["clipdemand"] = new Image(130,18);
offImgs["clipdemand"].src = "../image/topnav/clipdemand.gif";
offImgs["help"] = new Image(58,18);
offImgs["help"].src = "../image/topnav/help.gif";

}

	
function imgOn(imgName) {
        if (document.images) {
            document.images[imgName].src = onImgs[imgName].src;
        }
}

function imgOff(imgName) {
        if (document.images) {
            document.images[imgName].src = offImgs[imgName].src;
        }
}