if (document.images) {
     button1 = new Image
     button2 = new Image
     button3 = new Image
     button4 = new Image

     button1.src = 'wijnegem01.jpg'
     button2.src = 'wijnegem02.jpg'
     button3.src = 'merksem01.jpg'
     button4.src = 'merksem02.jpg'
 }