var trigger = 0;
var speed = 15;
var position = 100;
var listBackHeight = 785;
var listFrontHeight = 100;
var interval = 0;

function currencyUpDown() {
  if(trigger == 0){
      if(position >= listBackHeight){
		 clearTimeout(interval);
		 trigger = 1;
		 document.getElementById("controlCurrencyList").innerHTML = downString;
		 document.getElementById("weatherIcon").innerHTML="<img src=/images/button_up.jpg>";
	     return 1;
	  }
      position +=speed;
      document.getElementById("currencyListFront").style.height = position+"px";
	  interval = setTimeout(currencyUpDown,1)
   }
   if(trigger == 1){
	  if(position <= listFrontHeight){
		 clearTimeout(interval);
		 trigger = 0;
		 document.getElementById("controlCurrencyList").innerHTML = upString;
		 document.getElementById("weatherIcon").innerHTML="<img src=/images/button_down.jpg>";
	     return 1;
	  }
      position -=speed;
	  document.getElementById("currencyListFront").style.height = position+"px";
	  interval = setTimeout(currencyUpDown,1)
   }
   return 1;
}