var timerID = null;
	var popupOpen = 0;
	
	function ScrollUp(speed){ // window.status=document.getElementById('popup'+popupOpen).style.top;
	    if (parseInt(document.getElementById('popup'+popupOpen).style.top) < 0)
	 		document.getElementById('popup'+popupOpen).style.top = parseInt(document.getElementById('popup'+popupOpen).style.top) + speed + "px";
	    timerID = setTimeout("ScrollUp("+speed+")",30)
	}
	function ScrollDown(speed){ // window.status=document.getElementById('popup'+popupOpen).style.top;
	    if(parseInt(document.getElementById('popup'+popupOpen).style.top) > document.getElementById('scrollArea').offsetHeight - document.getElementById('popup'+popupOpen).offsetHeight) 
		    document.getElementById('popup'+popupOpen).style.top = parseInt(document.getElementById('popup'+popupOpen).style.top) - speed + "px";
	    timerID = setTimeout("ScrollDown("+speed+")",30)
	}
	function ScrollTop() { document.getElementById('popup'+popupOpen).style.top = 0 + 'px'; }
	function ScrollBottom() { document.getElementById('popup'+popupOpen).style.top = -(document.getElementById('popup'+popupOpen).offsetHeight) + parseInt(document.getElementById('popup').style.height) + 'px'; }
	function ScrollStop() { clearTimeout(timerID); }
	
	function popupVis() {
		if ((browser.ie4&&browser.mac)||browser.ie45||browser.ns4||browser.opera5||browser.opera6||browser.safari) {
			alert("This section of the Energy and Change Web site requires HTML 4-compliant browsers to function correctly.\n" +
				"\nPlease use Internet Explorer 5+ or Netscape 6+ to access the extra features on this page.");
			return;
		}//*/
		var popupWidth = (popupVis.arguments.length==4)? popupVis.arguments[2] : (browser.opera7)? 600: (document.styleSheets[0].cssRules)? parseInt(document.styleSheets[0].cssRules[0].style.width): (document.styleSheets[0].rules)? parseInt(document.styleSheets[0].rules[0].style.width): 600;
		var popupHeight = (popupVis.arguments.length==4)? popupVis.arguments[3] : (browser.opera7)? 150: (document.styleSheets[0].cssRules)? parseInt(document.styleSheets[0].cssRules[0].style.height): (document.styleSheets[0].rules)? parseInt(document.styleSheets[0].rules[0].style.height): 150;
		if (!(browser.ie5&&browser.mac)&&popupVis.arguments.length > 0) {
			document.getElementById('popup'+popupVis.arguments[0]).style.overflow = "auto";
			document.getElementById('popup'+popupVis.arguments[0]).style.height = popupHeight - 40 + "px";
			document.getElementById('popupScrollers').style.visibility = 'hidden';
		}//*/
		if (browser.ie5&&browser.mac) {
			document.getElementById('scrollArea').style.position = "absolute";
			document.getElementById('scrollArea').style.left = 5 + "px";
			document.getElementById('scrollArea').style.top = 25 + "px";
		}
		if (	(popupVis.arguments.length == 0) 
			||	(document.getElementById('popup'+popupVis.arguments[0]).style.visibility=='visible')	) {
			document.getElementById('popup'+popupOpen).style.visibility='hidden';
			document.getElementById('popup').style.visibility = 'hidden';
			popupOpen = 0;
			return;
		}
		else if (popupVis.arguments.length > 2) {
			document.getElementById('popup').style.width = popupVis.arguments[2];
			document.getElementById('popup').style.height = popupVis.arguments[3];
		}
		else {
			document.getElementById('popup').style.width = popupWidth;
			document.getElementById('popup').style.height = popupHeight;
		}

		document.getElementById('popup'+popupVis.arguments[0]).style.width = popupWidth - 30;
		document.getElementById('scrollArea').style.height = popupHeight - 30;
		
		document.getElementById('popup'+popupVis.arguments[0]).style.top = 0 + 'px';
		if (popupOpen != 0) document.getElementById('popup'+popupOpen).style.visibility='hidden';
		popupOpen = popupVis.arguments[0];

		// set popup headings according to content type
		if (popupVis.arguments[1]=='m') {
			document.getElementById('popup').style.backgroundColor = "#fcc";
			document.getElementById('popupHeading').style.color = "#900";
			//if (!(browser.ie5&&browser.mac))
				document.getElementById('popupHeading').innerHTML = "Overall management";
		}
		if (popupVis.arguments[1]=='g') {
			document.getElementById('popup').style.backgroundColor = "#ffc";
			document.getElementById('popupHeading').style.color = "#990";
			//if (!(browser.ie5&&browser.mac))
				document.getElementById('popupHeading').innerHTML = "At a glance";
		}
		if (popupVis.arguments[1]=='s') {
			document.getElementById('popup').style.backgroundColor = "#cfc";
			document.getElementById('popupHeading').style.color = "#090";
			//if (!(browser.ie5&&browser.mac))
				document.getElementById('popupHeading').innerHTML = "Strategies";
		}
		if (popupVis.arguments[1]=='h') {
			document.getElementById('popup').style.backgroundColor = "#ccf";
			document.getElementById('popupHeading').style.color = "#009";
			//if (!(browser.ie5&&browser.mac))
				document.getElementById('popupHeading').innerHTML = "Hints";
		}
		
		// set popup window position to center of visible page area
		if (browser.ns6) {
		/** NS6 does not recognise DOM2 objects:
		 **	a) 'document.body.clientWidth' and 'document.body.clientHeight'
		 **	b) 'document.body.scrollLeft' and 'document.body.scrollTop'
		 ** which must be replaced by a) 'window.inner{Width/Height}' and 'window.page{X/Y}Offset'
		//*/
			document.getElementById('popup').style.left = ((window.innerWidth/2)+window.pageXOffset)-(popupWidth/2);
			document.getElementById('popup').style.top = ((window.innerHeight/2)+window.pageYOffset)-(popupHeight/2);
		}
		else {
			document.getElementById('popup').style.left = (document.body.clientWidth/2+document.body.scrollLeft)-(popupWidth/2);
			document.getElementById('popup').style.top = (document.body.clientHeight/2+document.body.scrollTop)-popupHeight/2+1;
		}
		
		// make popup objects visible 
		document.getElementById('popup').style.visibility = 'visible';
		document.getElementById('popup'+popupVis.arguments[0]).style.visibility='visible';
/*			alert("0/" + 
				"\npopupCoord: " + document.getElementById('popup').style.left + ", " + document.getElementById('popup').style.top +
				"\nwinDim: " + document.body.clientWidth + " (" + (document.body.clientWidth/2) + "), " + document.body.clientHeight + " (" + (document.body.clientHeight/2) + ")" +
				"\nscroll: " + document.body.scrollLeft + ", " + document.body.scrollTop +
				"\npopupDim: " + popupWidth + " (" + popupWidth/2 + "), " + popupHeight + " (" + popupHeight/2 + ")" +
				"\nX: (" + document.body.clientWidth/2 + " + " + document.body.scrollLeft + ") = " + (parseInt(document.body.clientWidth)/2+parseInt(document.body.scrollLeft)) + " - " + parseInt(popupWidth)/2 +
				"\nY: (" + document.body.clientHeight/2 + " + " + document.body.scrollTop + ") = " + (parseInt(document.body.clientHeight)/2+parseInt(document.body.scrollTop)) + " - " + parseInt(popupHeight)/2); //*/

	}