var dsBarOffset=-1;

// expire old-format cookies
var oldCookieName=new Array("a=","9=","8=","7=","6=","5=","4=","3=","2=","1=");
for (n=0; n < oldCookieName.length; n++)
  document.cookie=oldCookieName[n]+"; path=/; expires=Mon, 1-Jan-2001 0:00:00 GMT;";
document.cookie="save=; path=/; expires=Mon, 1-Jan-2001 0:00:00 GMT;";
document.cookie="sort=; path=/; expires=Mon, 1-Jan-2001 0:00:00 GMT;";
var url=document.URL;
var idx=url.indexOf("dss.ucar.edu/datasets");
if ((idx == 7 || idx == 8) && document.title.indexOf("Document Not Found") == -1) {
  thisDsNum=url.substr(31,5);
  var idx=document.cookie.indexOf("dshist=");
// no dshist cookie
  if (idx == -1)
    document.cookie="dshist=n:l:"+thisDsNum+"; path=/;";
// dshist cookie exists
  else {
    var start=document.cookie.indexOf("dshist=");
    var len=document.cookie.substr(start,32768).indexOf(";");
    if (len == -1)
	len=32768;
    var dshist=document.cookie.substr(start,len);
// ds number not already in cookie
    if (dshist.indexOf(thisDsNum) == -1) {
	var save=dshist.charAt(7);
	var sort=dshist.charAt(9);
	switch (sort) {
	  case "l":
	    dshist=dshist.substr(0,10)+":"+thisDsNum+dshist.substr(10,32768);
	    if (dshist.length > 70)
		dshist=dshist.substr(0,70);
	    break;
	  case "f":
	    dshist+=":"+thisDsNum;
	    if (dshist.length > 70)
		dshist=dshist.substr(0,10)+dshist.substr(16,32768);
	    break;
	  case "a":
	    var addedDs=false;
	    for (n=10; n < dshist.length; n+=6) {
		var x=dshist.substr(n+1,5);
		if (parseFloat(thisDsNum) < parseFloat(x)) {
		  dshist=dshist.substr(0,n)+":"+thisDsNum+dshist.substr(n,32768);
		  addedDs=true;
		  n=dshist.length;
		}
	    }
	    if (!addedDs)
		dshist+=":"+thisDsNum;
	    if (dshist.length > 70) {
		if (addedDs)
		  dshist=dshist.substr(0,70);
		else
		  dshist=dshist.substr(0,10)+dshist.substr(16,32768);
	    }
	    break;
	  case "d":
	    var n=dshist.length-6;
	    var x=dshist.substr(n+1,5);
	    while (n > 10 && parseFloat(thisDsNum) > parseFloat(x)) {
		n-=6;
		x=dshist.substr(n+1,5);
	    }
	    if (parseFloat(thisDsNum) > parseFloat(x))
		dshist=dshist.substr(0,n)+":"+thisDsNum+dshist.substr(n,32768);
	    else
		dshist=dshist.substr(0,n+6)+":"+thisDsNum+dshist.substr(n+6,32768);
	    if (dshist.length > 70) {
		if (n == 10)
		  dshist=dshist.substr(0,70);
		else
		  dshist=dshist.substr(0,10)+dshist.substr(16,32768);
	    }
	    break;
	}
    }
    switch (save) {
	case "n":
	  document.cookie=dshist+"; path=/;";
	  break;
	case "y":
	  document.cookie=dshist+"; path=/; expires=Fri, 1-Jan-2010 0:00:00 GMT;";
	  break;
    }
  }
}

function dsNavImageOn(imgPrefix,isWhite)
{
  if (!isWhite) {
    if (document.layers)
	eval("document.images[\""+imgPrefix+"Img\"].src="+imgPrefix+"OnImage.src")
;
    else if (document.getElementById)
	eval("document.getElementById(\""+imgPrefix+"Img\").src="+imgPrefix+"OnImage.src");
  }
}

function dsNavImageOff(imgPrefix,isWhite)
{
  if (!isWhite) {
    if (document.layers)
	eval("document.images[\""+imgPrefix+"Img\"].src="+imgPrefix+"OffImage.src"
);
    else if (document.getElementById)
	eval("document.getElementById(\""+imgPrefix+"Img\").src="+imgPrefix+"OffImage.src");
  }
}