function popup(theURL, theWidth, theHeight, theTitle) {
  theParams = "width="+theWidth+",height="+theHeight+",scrollbars=yes,menubar=no";
  theParams += ",left="+(screen.availWidth / 2 - theWidth / 2)+",top="+(screen.availHeight / 2 - theHeight / 2);

  win = window.open(theURL, theTitle, theParams);
}



// Set up the image files to be used.
var theImages = new Array() // do not change this

theImages[0] = 'images/MTmiddle3.jpg'
theImages[1] = 'images/MTmiddle1.jpg'
theImages[2] = 'images/MTmiddle2.jpg'
theImages[3] = 'images/MTmiddle.jpg'


// do not edit anything below this line

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]+'" border=0 ISMAP USEMAP="Default.asp#freetrial" alt="Welcome to MedTRACK">');
}