function stopError() {
            return true;
          }

          window.onerror = stopError;

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v3.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}

function fixLayers() {
	if (navigator.appName == "Netscape") {
		if (parseFloat(navigator.appVersion) >= 4.5) {
			document.location.reload();
		} // End Check AppVersion
	}// End Check AppName
} // End fixLayers

function MM_showHideLayers() { //v3.0A Modified by Mark Cameron of McGraw-Hill for NN6 Compatibility
  var i,p,v,obj,args=MM_showHideLayers.arguments;if(document.getElementById){
   for (i=0; i<(args.length-2); i+=3){ obj=tmt_findObj(args[i]);v=args[i+2];
   v=(v=='show')?'visible':(v='hide')?'hidden':v;
   if(obj)obj.style.visibility=v;}} else{
  for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];
    if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v='hide')?'hidden':v; }
    obj.visibility=v; }}
}

function tmt_findObj(n){
	var x,t; if((n.indexOf("?"))>0&&parent.frames.length){t=n.split("?");
	x=eval("parent.frames['"+t[1]+"'].document.getElementById('"+t[0]+"')");
	}else{x=document.getElementById(n)}return x;
}

function selectURL() {
  var newURL = "";
  var currDate = new Date();
  //alert("Month is " + currDate.getMonth() + ", Date is " + currDate.getDate());
  // start here with later date first
    if (checkMonthDate(1, 9, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter17.shtml";
	} else if (checkMonthDate(1, 2, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter18.shtml";
    } else if (checkMonthDate(1, 9, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter19.shtml";
	} else if (checkMonthDate(1, 16, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter20.shtml";
	} else if (checkMonthDate(1, 23, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter21.shtml";
	} else if (checkMonthDate(1, 30, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter22.shtml";
	} else if (checkMonthDate(2, 6, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter23.shtml";
	} else if (checkMonthDate(2, 13, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter24.shtml";
  	} else if (checkMonthDate(2, 20, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter25.shtml";
  	} else if (checkMonthDate(2, 27, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter26.shtml";
	} else if (checkMonthDate(3, 6, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter01.shtml";
	} else if (checkMonthDate(3, 13, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter02.shtml";
	} else if (checkMonthDate(3, 20, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter03.shtml";
	} else if (checkMonthDate(3, 27, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter04.shtml";
	} else if (checkMonthDate(4, 3, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter05.shtml";
	} else if (checkMonthDate(4, 10, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter06.shtml";
	} else if (checkMonthDate(4, 17, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter07.shtml";
	} else if (checkMonthDate(5, 1, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter08.shtml";
	} else if (checkMonthDate(5, 8, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter09.shtml";
	} else if (checkMonthDate(5, 15, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter10.shtml";
	} else if (checkMonthDate(5, 22, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter11.shtml";
	} else if (checkMonthDate(5, 29, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter12.shtml";
	} else if (checkMonthDate(6, 5, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter13.shtml";
	} else if (checkMonthDate(8, 1, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter14.shtml";
	} else if (checkMonthDate(8, 22, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter01.shtml";
	} else if (checkMonthDate(8, 29, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter02.shtml";
	} else if (checkMonthDate(9, 5, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter03.shtml";
	} else if (checkMonthDate(9, 12, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter04.shtml";
	} else if (checkMonthDate(9, 19, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter05.shtml";
	} else if (checkMonthDate(9, 26, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter06.shtml";
	} else if (checkMonthDate(10, 3, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter07.shtml";
	} else if (checkMonthDate(10, 10, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter08.shtml";
	} else if (checkMonthDate(10, 17, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter09.shtml";
	} else if (checkMonthDate(10, 24, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter10.shtml";
	} else if (checkMonthDate(10, 31, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter11.shtml";
	} else if (checkMonthDate(11, 7, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter12.shtml";
	} else if (checkMonthDate(11, 14, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter13.shtml";
	} else if (checkMonthDate(11, 21, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter14.shtml";
	} else if (checkMonthDate(12, 5, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter15.shtml";
	} else if (checkMonthDate(12, 12, currDate)) {
  		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter16.shtml";
	} else {
		window.location = "http://www.glencoe.com/sec/science/chemistry/mc/pow/chapter01.shtml";
	}
}

// returns true if month and date supplied is after current date
function checkMonthDate(month1, date1, currDate) {
	var bool0 = false;
	month1 = month1 - 1;

	compDate = new Date();
	compDate.setYear(currDate.getYear());
	compDate.setMonth(month1);
	compDate.setDate(date1);

	var currDate2 = currDate.getTime() - (7 * 24 * 60 * 60 * 1000);
	//alert(currDate2);
	if (compDate.getTime() >= currDate2) {
		//alert("date " + compDate.getMonth() + " " + compDate.getDate() + " is true");
		return true;
	}
}



 function openItTool(url)

 {

 varnewWin=window.open(url,"","resizable=yes,menubar=no,toolbar=no,width=520,height=400,scrollbars=yes");

 }