.getElementsByTagName("span");
	for (var i=0; i < spans.length; i++) {
	    var elem = spans[i];
	    if (elem) {
		var level = elem.getAttribute("class");
                if (level == "h1" || level == "h2" || level == "h3" || level == "h4" || level == "h5" || level == "h6") {
                    elem.innerHTML = "<"+level+">"+elem.innerHTML+"</"+level+">";		
                }
	    }
	}
    }
    var legend_html = "Colour legend:<br />      <table>         <tr><td>Unknown:</td>                   <td><span c