var theImages = new Array() 

theImages[0] = '/~educ/images/spotPhotos/01.gif'
theImages[1] = '/~educ/images/spotPhotos/02.gif'
theImages[2] = '/~educ/images/spotPhotos/03.gif'
theImages[3] = '/~educ/images/spotPhotos/04.gif'
theImages[4] = '/~educ/images/spotPhotos/05.gif'
theImages[5] = '/~educ/images/spotPhotos/06.gif'
theImages[6] = '/~educ/images/spotPhotos/07.gif'
theImages[7] = '/~educ/images/spotPhotos/08.gif'
theImages[8] = '/~educ/images/spotPhotos/09.gif'
theImages[9] = '/~educ/images/spotPhotos/10.gif'
theImages[10] = '/~educ/images/spotPhotos/11.gif'
theImages[11] = '/~educ/images/spotPhotos/12.gif'
theImages[12] = '/~educ/images/spotPhotos/13.gif'
theImages[13] = '/~educ/images/spotPhotos/14.gif'
theImages[14] = '/~educ/images/spotPhotos/15.gif'
theImages[15] = '/~educ/images/spotPhotos/16.gif'
theImages[16] = '/~educ/images/spotPhotos/17.gif'
theImages[17] = '/~educ/images/spotPhotos/18.gif'

var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="'+theImages[whichImage]+'">');
}