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
     button9 = new Image
     button10 = new Image

     button1.src = '../images/btn_why_michelin.gif'
     button2.src = '../images/btn_why_michelin_o.gif'
     button3.src = '../images/btn_news.gif'
     button4.src = '../images/btn_news_o.gif'
     button5.src = '../images/btn_comfort.gif'
     button6.src = '../images/btn_comfort_o.gif'
     button7.src = '../images/btn_michelin_tech.gif'
     button8.src = '../images/btn_michelin_tech_o.gif'
     button9.src = '../images/btn_environment.gif'
     button10.src = '../images/btn_environment_o.gif'
 }