if (document.images) 
{ 

    //preload images 

    //base image 

    HomeButN = new Image(89,44); 
    HomeButN.src = './images/Home.jpg' ; 
    AUButN = new Image(137,44); 
    AUButN.src = './images/About-Us.jpg' ; 
   NewsButN = new Image(102,44); 
   NewsButN.src = './images/News.jpg' ; 
   PortButN = new Image(152,44); 
    PortButN.src = './images/Portfolio.jpg' ; 
    ContactButN = new Image(134,44); 
    ContactButN.src = './images/Contact.jpg' ; 
     
   
    //hover or rollover images

    HomeButH = new Image(89,44); 
    HomeButH.src = './images/Home_Hover.jpg' ;
    AUButH = new Image(137,44); 
    AUButH.src = './images/About-Us_Hover.jpg' ; 
    NewsButH = new Image(102,44); 
    NewsButH.src = './images/News_Hover.jpg' ;
   PortButH  = new Image(152,44); 
    PortButH.src = './images/Portfolio_Hover.jpg';
    ContactButH = new Image(134,44); 
    ContactButH.src = './images/Contact_Hover.jpg' ;

   function myOn(myImgName) 
    { 
        //we need to name the image in the BODY 
        //so we can use its name here 
        document[myImgName].src=eval(myImgName+ 'H' ).src; 
    } 

    function myOut(myImgName) 
    { 
        document[myImgName].src=eval(myImgName+ 'N' ).src; 
    } 

} //end of if document.images