if (document.images) {
            button1 = new Image; button2 = new Image; button3 = new Image; button4 = new Image; button5 = new Image;
            button6 = new Image; button7 = new Image; button8 = new Image; 
            
            button1.src = 'images/home_off.gif'
            button2.src = 'images/home_on.jpg'
            button3.src = 'images/services_off.gif'
            button4.src = 'images/services_on.jpg'
            button5.src = 'images/about_off.gif'
            button6.src = 'images/about_on.jpg'
            button7.src = 'images/media.jpg'
            button8.src = 'images/media_on.jpg'
        }