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

     button1.src = 'images/demo_commercial.gif'
     button2.src = 'images/demo_commercial_r.gif'
     
      button3 = new Image
     button4 = new Image

     button3.src = 'images/demo_promo.gif'
     button4.src = 'images/demo_promo_r.gif'
     
     button5 = new Image
     button6 = new Image

     button5.src = 'images/demo_narration.gif'
     button6.src = 'images/demo_narration_r.gif'
     
      button7 = new Image
     button8 = new Image

     button7.src = 'images/demo_animation.gif'
     button8.src = 'images/demo_animation_r.gif'
     
     
     
     
     
     
 }