if (document.images) {
     button1 = new Image
     button2 = new Image
     
     button1.src = 'img/welcome.png'
     button2.src = 'img/welcome2.png'

     button3 = new Image
     button4 = new Image

     button3.src = 'img/menus.png'
     button4.src = 'img/menus2.png'

     button5 = new Image
     button6 = new Image

     button5.src = 'img/events.png'
     button6.src = 'img/events2.png'

     button7 = new Image
     button8 = new Image

     button7.src = 'img/history.png'
     button8.src = 'img/history2.png'

     button9 = new Image
     button10 = new Image

     button9.src = 'img/contact.png'
     button10.src = 'img/contact2.png'
 }