var timerlen = 5;
var slideAniLen = 300;

var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var endWidth = 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
 
  moving[objname] = true;
  dir[objname] = "down";
  startSlide(objname);
}

function slideLeft(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] = "left";
  startSlide(objname);
}

function slideRight(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] = "right";
  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);
  endWidth[objname] = parseInt(obj[objname].style.width);
  startTime[objname] = (new Date()).getTime();
 
  if(dir[objname] == "down"){
    obj[objname].style.height = "1px";
  }
  
  if(dir[objname] == "right"){
    obj[objname].style.width = "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 {
    if (dir[objname] == "up" || dir[objname]=="down"){
		var d =Math.round(elapsed / slideAniLen * endHeight[objname]);
		if(dir[objname] == "up")
		  d = endHeight[objname] - d;
	 
		obj[objname].style.height = d + "px";
	}else{
		var d =Math.round(elapsed / slideAniLen * endWidth[objname]);
		if(dir[objname] == "left")
		  d = endWidth[objname] - d;
		obj[objname].style.width = d + "px";
	}
  }
 
  return;
}

function endSlide(objname){
  clearInterval(timerID[objname]);
 
  if(dir[objname] == "up" || dir[objname] == "left")
    obj[objname].style.display = "none";
 
  obj[objname].style.height = endHeight[objname] + "px";
  obj[objname].style.width = endWidth[objname] + "px";
 
  delete(moving[objname]);
  delete(timerID[objname]);
  delete(startTime[objname]);
  delete(endHeight[objname]);
  delete(endWidth[objname]);
  delete(obj[objname]);
  delete(dir[objname]);
 
  return;
}