function Is() {
    var agent = navigator.userAgent.toLowerCase();
    this.major = parseInt(navigator.appVersion);
    this.minor = parseFloat(navigator.appVersion);
    this.ns  = ((agent.indexOf('mozilla')!=-1) && ((agent.indexOf('spoofer')==-1) && (agent.indexOf('compatible') == -1)));
    this.ns2 = (this.ns && (this.major == 2));
    this.ns3 = (this.ns && (this.major == 3));
    this.ns4b = (this.ns && (this.minor < 4.04));
    this.ns4 = (this.ns && (this.major >= 4));
    this.ie   = (agent.indexOf("msie") != -1);
    this.ie3  = (this.ie && (this.major == 2));
    this.ie4  = (this.ie && (this.major >= 4));
    this.op3 = (agent.indexOf("opera") != -1);
    this.win   = (agent.indexOf("win")!=-1);
    this.mac   = (agent.indexOf("mac")!=-1);
    this.unix  = (agent.indexOf("x11")!=-1);
}

var is = new Is();

function onerror() {
    document.location.href = "javascript:";
}

if(is.ns4) {
    doc = "document";
    sty = "";
    htm = ".document"
} else if(is.ie4) {
    doc = "document.all";
    sty = ".style";
    htm = ""
}


<!-------
function positionLayers() {
    baseObj = eval(doc + '["baseLayer"]' + sty);
    baseObj.left = 0;
    baseObj.top = 0;

    bottomObj = eval(doc + '["bottomBorder"]' + sty);
    //bottomObj.left = available_width+0;
    //bottomObj.top = available_height+800;

    textObj = eval(doc + '["textLayer"]' + sty);
    //textObj.left = available_width+0;
    //textObj.top = available_height+150;

    chemObj = eval(doc + '["moleculeLayer"]' + sty);
    //chemObj.left = available_width-491;
    //chemObj.top = available_height+410;

    labelObj = eval(doc + '["labelLayer"]' + sty);
    //labelObj.left = available_width-446;
    //labelObj.top = available_height+650;

    menuObj = eval(doc + '["menuLayer"]' + sty);
    //menuObj.left = available_width+0;
    //menuObj.top = available_height+100;

    barObj = eval(doc + '["barLayer"]' + sty);
    //barObj.left = available_width+0;
    //barObj.top = available_height+100;

    contactObj = eval(doc + '["contactLayer"]' + sty);
    //contactObj.left = available_width+0;
    //contactObj.top = available_height+690;

    baseObj.visibility = "visible";
    bottomObj.visibility = "visible";
    chemObj.visibility = "visible";
    textObj.visibility = "visible";
    menuObj.visibility = "visible";
    labelObj.visibility = "visible";
    barObj.visibility = "visible";	

}
--->