var imHeads;

	 var swapIm3 = new Array();
	 var swapIm4 = new Array();
	 var old = "";
	 var oldSrc = "";
	 var old2 = "";
	 var oldSrc2 = "";

	 var Im3= new Array(
	 	"/images/timeline/1900_lit.gif", 
		"/images/timeline/1910_lit.gif", 
		"/images/timeline/1920_lit.gif", 
		"/images/timeline/1930_lit.gif", 
		"/images/timeline/1940_lit.gif", 
		"/images/timeline/1950_lit.gif", 
		"/images/timeline/1960_lit.gif", 
		"/images/timeline/1970_lit.gif", 
		"/images/timeline/1980_lit.gif", 
		"/images/timeline/1990_lit.gif", 
		"/images/timeline/2000_lit.gif"
		 );

	 var Im4= new Array(
	 	"/images/timeline/1900_main.gif", 
		"/images/timeline/1910_main.gif", 
		"/images/timeline/1920_main.gif", 
		"/images/timeline/1930_main.gif", 
		"/images/timeline/1940_main.gif", 
		"/images/timeline/1950_main.gif", 
		"/images/timeline/1960_main.gif", 
		"/images/timeline/1970_main.gif", 
		"/images/timeline/1980_main.gif", 
		"/images/timeline/1990_main.gif", 
		"/images/timeline/2000_main.gif"
		 );


   	for(i in Im3) {
      swapIm3[i] = new Image();
	  swapIm3[i].src = Im3[i];
   }
 


   	for(i in Im4) {
      swapIm4[i] = new Image();
	  swapIm4[i].src = Im4[i];
   }


   	function swap3(n,index) {

     n = arguments[0].toString();
	 index = parseInt(arguments[1]);
	 eval("oldSrc = document." + n + ".src");
	 old = n;
 
	 eval("document." + n + " .src=swapIm3[" + index + "].src");
	 }

   
   	function swap4(n,index) {

     n = arguments[0].toString();
	 index = parseInt(arguments[1]);

	 eval("document." + n + " .src=swapIm4[" + index + "].src");
	 }

   
   function back3() {

     eval("document." + old + ".src=oldSrc");
    }


function MM_reloadPage(init) {  //reloads the window if Nav4 resized
  if (init==true) with (navigator) {if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
    document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }}
  else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
}
MM_reloadPage(true);
// -->

function MM_findObj(n, d) { //v4.0
  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);
  if(!x && document.getElementById) x=document.getElementById(n); return x;
}

function hideAll(){
var MyObj, D, v
for (i=1;i<=12;i++){
	var D = "Layer" + i;
		 Myobj=MM_findObj(D)
		if( Myobj != null){
		    if (Myobj.style) { Myobj=Myobj.style; v=(v=='show')?'visible':(v='hide')?'hidden':v; }
    			if (!v){v="hide";}
				Myobj.visibility=v;
				//alert(v);
		}
	}
}
function MM_showHideLayers() { //v3.0
hideAll();
  var i,p,v,obj,args=MM_showHideLayers.arguments;
  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; }
}