var Pics = new Array()

Pics[0] = 'images/header_pic1.jpg'
Pics[1] = 'images/header_pic2.jpg'
Pics[2] = 'images/header_pic3.jpg'
Pics[3] = 'images/header_pic4.jpg'
Pics[4] = 'images/header_pic5.jpg'
Pics[5] = 'images/header_pic6.jpg'
Pics[6] = 'images/header_pic7.jpg'
Pics[7] = 'images/header_pic8.jpg'
Pics[8] = 'images/header_pic9.jpg'
Pics[9] = 'images/header_pic10.jpg'
Pics[10] = 'images/header_pic11.jpg'

var AltPics = new Array()

AltPics[0]="ProGrad"
AltPics[1]="ProGrad"
AltPics[2]="ProGrad"
AltPics[3]="ProGrad"
AltPics[4]="ProGrad"
AltPics[5]="ProGrad"
AltPics[6]="ProGrad"
AltPics[7]="ProGrad"
AltPics[8]="ProGrad"
AltPics[9]="ProGrad"
AltPics[10]="ProGrad"

var c = Pics.length;

var onLoad = new Array()

for (i = 0; i < c; i++){
   onLoad[i] = new Image()
   onLoad[i].src = Pics[i]
}

function DisplayPic(){
	var ImageChoice = Math.round(Math.random()*(c-1));
	document.write('<img src="http://www.prograd.com.au/'+Pics[ImageChoice]+'" alt="'+AltPics[ImageChoice]+'">');
}