//constants
var REV_CYCLE = 500;	//time betwin checking contents
var MAX_CHANGE = 10;	//number of cycles that did not cause an advert display

//Std variables
var ns4 = (document.layers);
var ie4 = (document.all && !document.getElementById);
var ie5 = (document.all && document.getElementById);
var ns6 = (!document.all && document.getElementById);

var advTop = [0,1];	//adv top has two adverts, starting with adverts 0 and 1
var tmpNum = [0,0];
			  
var timerID = 0;
var changes = 0;
var displaySet = 0;
var curDisplay = -1;
curDisplay = Math.round(5*Math.random());
var mFrame = window;
try {
	//mFrame = window.parent.frames['mainFrame'];
}
catch (e) {}
var frameCont = mFrame.location.href;
//var advDiv = document.getElementByID( "adv1");
var adv = new Array();
adv[adv.length] = ['/hsd/hsdCLI.nsf/UNI/NT00005286?OpenDocument&sub=busDisp', '/hst/clients/medtel/MedTelStrap2.gif', '_blank'];
adv[adv.length] = ['http://www.publicclass.com', '/hst/images/pcs_logo.gif', '_blank'];
adv[adv.length] = ['http://alliance.harleystreet.com/hst/alliance/default.html', '/hst/images/adverts/alliance.gif', '_blank'];
//adv[adv.length] = ['http://www.advancevisioncare.co.uk', 'images/adverts/adv_image_care.gif', '_blank'];

//var advSets = new Array();
//advSets[advSets.length] = [0,1];
//advSets[advSets.length] = [0,2];
//advSets[advSets.length] = [1,2];

function UpdateTimer() {
	changes++;
	if (mFrame.location.href != frameCont || changes > MAX_CHANGE) {
		frameCont = mFrame.location.href;
		changeAdvs();
		changes = 0;
	}	
	timerID = setTimeout("UpdateTimer()", REV_CYCLE);
}
function changeAdvs() {
	//if (displaySet >= advSets.length) displaySet = 0;
	if (curDisplay >= (adv.length-1)) curDisplay = -1; //a reset
	curDisplay = curDisplay + 1; //we advance
	tmpNum[0] = curDisplay;
	if (curDisplay == (adv.length-1)) tmpNum[1] = 0; else tmpNum[1] = curDisplay + 1;
	if (advTop[0] == tmpNum[1] || advTop[1] == tmpNum[0]) {  //do a bit of fliping
		advTop[0] = tmpNum[1];
		advTop[1] = tmpNum[0];
	} else {
		advTop[0] = tmpNum[0];
		advTop[1] = tmpNum[1];
	}
	
	var newHTML = '';
	tblHTML = '<table width="400" height="58" border="0" cellpadding="4" cellspacing="0"><tr>';
	advNum = advTop[0];
	//alert( advNum );
	newHTML = '<td><a href="' + adv[advNum][0] + '" target="' + adv[advNum][2] + '"><img src="' + adv[advNum][1] + '" border="0" /></a></td>'
	advNum = advTop[1];
	//alert( advNum );
	//newHTML1 = '<td><a href="' + adv[advNum][0] + '" target="' + adv[advNum][2] + '"><img src="' + adv[advNum][1] + '" border="0" /></a></td>'
	tblHTMLcls = '</tr></table>';
	//alert( frameCont );
	//document.getElementById( "adv1").style.visibility = "hidden"; //
	document.getElementById("advTop").innerHTML= tblHTML + newHTML  + tblHTMLcls; //advBlock1;
	//displaySet++;
}

function changeAdvsOld() {
	//if (displaySet >= advSets.length) displaySet = 0;
	if (curDisplay >= (adv.length-1)) curDisplay = -1; //a reset
	curDisplay = curDisplay + 1; //we advance
	tmpNum[0] = curDisplay;
	if (curDisplay == (adv.length-1)) tmpNum[1] = 0; else tmpNum[1] = curDisplay + 1;
	if (advTop[0] == tmpNum[1] || advTop[1] == tmpNum[0]) {  //do a bit of fliping
		advTop[0] = tmpNum[1];
		advTop[1] = tmpNum[0];
	} else {
		advTop[0] = tmpNum[0];
		advTop[1] = tmpNum[1];
	}
	
	var newHTML = '';
	tblHTML = '<table width="800" height="58" border="0" cellpadding="4" cellspacing="0"><tr>';
	advNum = advTop[0];
	//alert( advNum );
	newHTML = '<td><a href="' + adv[advNum][0] + '" target="' + adv[advNum][2] + '"><img src="' + adv[advNum][1] + '" border="0" /></a></td>'
	advNum = advTop[1];
	//alert( advNum );
	newHTML1 = '<td><a href="' + adv[advNum][0] + '" target="' + adv[advNum][2] + '"><img src="' + adv[advNum][1] + '" border="0" /></a></td>'
	tblHTMLcls = '</tr></table>';
	//alert( frameCont );
	//document.getElementById( "adv1").style.visibility = "hidden"; //
	document.getElementById("advTop").innerHTML= tblHTML + newHTML + newHTML1 + tblHTMLcls; //advBlock1;
	//displaySet++;
}

changeAdvs();	//display the first adverts
timerID  = setTimeout("UpdateTimer()", REV_CYCLE);