var timerextra = null;
  var objextra = null;
  var runningextra = false;
	var max = 80;
	var min = 0;
	var ind = 0; 
	var add = 0;
	
	function move_extra(){
	
  	objextra = document.getElementById("extra")
		ind = parseInt(objextra.style.height.replace("px",""));
	
		if (ind==min && !runningextra){
  		objextra.style.display = "block";
			add = 5;
		}
		if (ind==max && !runningextra){
			add = -5;
		}
		
		runningextra = true;
 		objextra.style.height = ind + add + "px";
		ind = parseInt(objextra.style.height.replace("px",""));
		
		if ((ind==min || ind==max) && runningextra){
		  window.clearTimeout(timerextra);
			runningextra = false;
			if (ind==min){
  			objextra.style.display = "none";
			}
		}
		else{
			timerextra = window.setTimeout("move_extra()", 10);
		}
	}