function next(array) {
  if (array[i]!=undefined)
  {
  		return array[i];
  }
  else return "";
}
		
function writeTable(continentID, array) {
  document.write("<div id=\"" + continentID + "\"style=\"display:none\">");
  array.sort();
  document.write("<table>");
	for (i=0;i<array.length;i++) {		
			document.write("<tr><td class=\"ref\">"+next(array)+"</td><td class=\"spacer\"></td>")
			i++;
			document.write("<td class=\"ref\">"+next(array)+"</td></tr>")
	}
	document.write("</table>");
	document.write("</script></div>");
}

function toggleDiv(divid, referenceCategories){
    if(document.getElementById(divid).style.display == 'none'){
		  for (i = 0; i < referenceCategories.length; i++) {
					document.getElementById(referenceCategories[i]).style.display = 'none';
					document.getElementById(referenceCategories[i] + "link").className = '';
			}
      document.getElementById(divid).style.display = 'block';
			document.getElementById(divid + "link").className = 'static';
    }else{
      document.getElementById(divid).style.display = 'none';
			document.getElementById(divid + "link").className = '';
    }
}

referenceCategories = new Array(
"Africa",
"America",
"Asia",
"Australia",
"China",
"Europe"
);

document.write("<div id='ref_navi'>");
for (i = 0; i < referenceCategories.length; i++) {
		document.write("<a id=\"" + referenceCategories[i] + "link\" href=\"javascript:;\" onmousedown=\"toggleDiv('" +
		referenceCategories[i] + "', referenceCategories);\">" + referenceCategories[i] + "</a>\n");
}
document.write("</div>");

writeTable("Africa", africa);
writeTable("America", america);
writeTable("Asia", asia);
writeTable("Australia", australia);
writeTable("China", china);
writeTable("Europe", europe);