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
  button11 = new Image
  button12 = new Image
  button13 = new Image
  button14 = new Image
  button15 = new Image
  button16 = new Image
  button17 = new Image
  button18 = new Image
  button19 = new Image
  button20 = new Image

  
  
  button1.src = 'images/nav1.jpg'
  button2.src = 'images/nav1a.jpg'
  button3.src = 'images/nav2.jpg'
  button4.src = 'images/nav2a.jpg'
  button5.src = 'images/nav3.jpg'
  button6.src = 'images/nav3a.jpg'
  button7.src = 'images/nav4.jpg'
  button8.src = 'images/nav4a.jpg'
  button9.src = 'images/nav5.jpg'
  button10.src = 'images/nav5a.jpg'
  button11.src = 'images/nav6.jpg'
  button12.src = 'images/nav6a.jpg'
  button13.src = 'images/nav7.jpg'
  button14.src = 'images/nav7a.jpg'
  button15.src = 'images/nav8.jpg'
  button16.src = 'images/nav8a.jpg'
  button17.src = 'images/nav9.jpg'
  button18.src = 'images/nav9a.jpg'
  button19.src = 'images/nav10.jpg'
  button20.src = 'images/nav10a.jpg'


  
  
}
else {

button1=""
button2=""
button3=""
button4=""
button5=""
button6=""
button7=""
button8=""
button9=""
button10=""
button11=""
button12=""
button13=""
button14=""
button15=""
button16=""
button17=""
button18=""
button19=""
button20=""


document.i=""
document.ii=""
document.iii=""
document.iv=""
document.v=""
document.vi=""
document.vii=""
document.viii=""
document.ix=""
document.x=""




}