var displayType = "block";
var html_open = '<img src="images/navi_plus.gif" alt="open" title="show" border="0"/>';
var html_close = '<img src="images/navi_minus.gif" alt="close" title="hide" border="0"/>';
function display(objName, label){
    var linkObj = document.getElementById(objName+"_link");
    var mode, txt;
    if ((obj=document.getElementById(objName))!=null){
        if (obj.style.display == displayType){ 
           mode="none"; txt=html_open;
        } else {
           mode=displayType; txt=html_close;
        }
        obj.style.display = mode;
        linkObj.innerHTML = txt+" "+label;
    } else {
        alert("Can't display \""+objName+"\". Object not found.");
    }
}
function expLink(targetId, label){
  var link = '<a href="javascript:display(\''+targetId+'\',\''+label+'\')" class="expand_link" id="'+targetId+'_link">'+html_open+" "+label+'</a>';  
  document.open();
  document.write(link);
  document.close();
}