function imgON(imagename){
    if(document.getElementById(imagename)){
	  document.getElementById(imagename).src = 'images/hnav/r_'+imagename+'.png';
 	  return false;
	}
  }
  
  function imgOFF(imagename){
    if(document.getElementById(imagename)){
        document.getElementById(imagename).src = 'images/hnav/' + imagename + '.png';
 	  return false;
	}
  }
  
  function VNAVimgON(imagename){
    if(document.getElementById(imagename)){
        document.getElementById(imagename).src = 'images/vnav/r_' + imagename + '.png';
 	  return false;
	}
  }
  
  function VNAVimgOFF(imagename){
    if(document.getElementById(imagename)){
        document.getElementById(imagename).src = 'images/vnav/' + imagename + '.png';
 	  return false;
	}
  }
  
  function togglediv(myelement) {
		if (document.getElementById(myelement).style.display == 'none') {
			document.getElementById(myelement).style.display = 'block';
		} else {
			document.getElementById(myelement).style.display = 'none';
		}
	}

	function updateStateProv(country) {
		if (country == "Canada") {
			document.getElementById("trProvince").style.display = "block";
			document.getElementById("trState").style.display = "none";
		} else if (country == "United States of America") {
			document.getElementById("trProvince").style.display = "none";
			document.getElementById("trState").style.display = "block";
		} else {
			document.getElementById("trProvince").style.display = "none";
			document.getElementById("trState").style.display = "none";
		}	
	}
	
	// calculate the modified Julian day number from Gregorian date

function julianDay(year,month,day) {
	alert(year + ' ' + month + ' ' + day);
        var extra = 100.0*year+month-190002.5;
        var julian = 367.0*year;
        julian -= Math.floor(7.0*(year+Math.floor((month+9.0)/12.0))/4.0);
        julian += Math.floor(275.0*month/9.0);
        julian += day;
        julian -= 678985.5;
        julian -= 0.5*extra/Math.abs(extra);
        return julian;
}

function diffDate(y,m,d) {
        sj = julianDay(new Date().getFullYear(),new Date().getMonth(),new Date().getDate());
        ej = julianDay(y,m,d);
        // note that month starts at zero (not one like you're used to) so in this case 9 = October
        if (ej>sj) {
          if(document.getElementById) {
            if(document.getElementById("displayDate")) {
              document.getElementById("displayDate").innerHTML  = "<span>"+(ej-sj)+"</span>";
            }
          }
        } else {
          if(document.getElementById) {
            if(document.getElementById("displayDate")) {
              document.getElementById("displayDate").innerHTML  = "<span>"+(sj-ej)+"</span>";
            }
          }
        }
}