//load control images
var Pic = new Array
Pic[0] = 'images/button1_3.png'
Pic[1] = 'images/button1_2.png'
Pic[2] = 'images/button1.png'
Pic[3] = 'images/button2_3.png'
Pic[4] = 'images/button2_2.png'
Pic[5] = 'images/button2.png'
Pic[6] = 'images/button3_3.png'
Pic[7] = 'images/button3_2.png'
Pic[8] = 'images/button3.png'
//declare control variables
var p = Pic.length
var preLoad = new Array()
var i = 0;
//preload array
for (i = 0; i < p; i++){
     preLoad[i] = new Image()
     preLoad[i].src = Pic[i]
}
//switch images on call
function switchImage(whichImage,imageNumber){
   document.images[whichImage].src = preLoad[imageNumber].src
}
//load main images
var image1=new Image()
image1.src="images/slide_1.jpg"
var image2=new Image()
image2.src="images/slide_2.jpg"
var image3=new Image()
image3.src="images/slide_3.jpg"