if (document.images) {
            
            img1on=new Image();          
            img1on.src="/buttons/images/toc1on.jpg";     
            img1off=new Image();         
            img1off.src="/buttons/images/toc1off.jpg";    
            img1ad=new Image();         
            img1ad.src="/buttons/images/splash1.jpg";   

            img2on=new Image();          
            img2on.src="/buttons/images/toc2on.jpg";     
            img2off=new Image();         
            img2off.src="/buttons/images/toc2off.jpg";    
            img2ad=new Image();         
            img2ad.src="/buttons/images/splash2.jpg";   

            img3on=new Image();          
            img3on.src="/buttons/images/toc3on.jpg";     
            img3off=new Image();         
            img3off.src="/buttons/images/toc3off.jpg";    
            img3ad=new Image();         
            img3ad.src="/buttons/images/splash3.jpg";   

            img4on=new Image();          
            img4on.src="/buttons/images/toc4on.jpg";     
            img4off=new Image();         
            img4off.src="/buttons/images/toc4off.jpg";    
            img4ad=new Image();         
            img4ad.src="/buttons/images/splash4.jpg";
      
            
        }

function imgOn(imgName) {
        if (document.images) {
            document[imgName].src=eval(imgName + "on.src");
            document["holder"].src=eval(imgName + "ad.src");
        }
}

function imgOff(imgName) {
        if (document.images) {
            document[imgName].src=eval(imgName + "off.src");
            document["holder"].src="/buttons/images/insightoffice.jpg";
                    
}
}