/*credit: http: //www.harrymaugans.com/2007/03/06/how-to-create-an-animated-sliding-collapsible-div-with-javascript-and-css/*/

var timerlen = 5;
var slideAniLen = 333;

var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var moving = new Array();
var dir = new Array();

function slidedown(objname) {
    if (moving[objname])
        return;

    if (document.getElementById(objname).style.display != "none")
        return; // cannot slide down something that is already visible
    document.getElementById(objname).style.visibility = "visible";

    moving[objname] = true;
    dir[objname] = "down";
    startslide(objname);
}

function slideup(objname) {
    if (moving[objname])
        return;

    if (document.getElementById(objname).style.display == "none")
        return; // cannot slide up something that is already hidden

    moving[objname] = true;
    dir[objname] = "up";
    startslide(objname);
}

function startslide(objname){
   obj[objname] = document.getElementById(objname);
  
   endHeight[objname] = parseInt(obj[objname].style.height);
   startTime[objname] = (new Date()).getTime();
  
   if(dir[objname] == "down"){
     obj[objname].style.height = "1px";
   }
  
   obj[objname].style.display = "block";
  
   timerID[objname] = setInterval("slidetick('" + objname + "');",timerlen);
 }

function slidetick(objname){
   var elapsed = (new Date()).getTime() - startTime[objname];
  
   if (elapsed > slideAniLen)
     endSlide(objname)
   else {
     var d =Math.round(elapsed / slideAniLen * endHeight[objname]);
     if(dir[objname] == "up")
       d = endHeight[objname] - d;
  
     obj[objname].style.height = d + "px";
   }
  
   return;
 }
 
 function endSlide(objname){
   clearInterval(timerID[objname]);

   if (dir[objname] == "up") {
       obj[objname].style.display = "none";
       document.getElementById(objname).style.visibility = "hidden";
   }
  
   obj[objname].style.height = endHeight[objname] + "px";
  
   delete(moving[objname]);
   delete(timerID[objname]);
   delete(startTime[objname]);
   delete(endHeight[objname]);
   delete(obj[objname]);
   delete(dir[objname]);
  
   return;
 }