// javascript used for state menu
// adelaney 6/18/2007
// from article: http://www.harrymaugans.com/2007/03/06/how-to-create-an-animated-sliding-collapsible-div-with-javascript-and-css/

//declare some initial variables for speed of animation

//how often the javascript funciton will run to alter the DIV's properties
var timerlen = 5; 

//how long it shoudl take a div to completely slide up or slide down
var slideAniLen = 500;

//used throughout the code below to keep track of our animations
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 to slide down
function slidedown(objname){
  if(moving[objname])
    return;
 
  if(document.getElementById(objname).style.display != "none")
    return; // cannot slide down something that is already visible
 
  moving[objname] = true;
  dir[objname] = "down";
  startslide(objname);
  
}
 
 //function to slide up
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);
  }

//begins the sliding process
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);
}

//does the animation
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;
}

//called when time runs out on animation
function endSlide(objname){
  clearInterval(timerID[objname]);
 
  if(dir[objname] == "up")
    obj[objname].style.display = "none";
 
  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;
}

//for toggle
function toggleSlide(objname){
  if(document.getElementById(objname).style.display == "none"){
    // div is hidden, so let's slide down
    slidedown(objname);
  }else{
    // div is not hidden, so slide up
    slideup(objname);
  }
}