function startLoading(mainAreaInternal, mainAreaLoading) {
	  Element.show(mainAreaLoading);
	  Element.hide(mainAreaInternal);
	}
	function finishLoading(mainAreaInternal, mainAreaLoading) {
	  Element.show(mainAreaInternal);
	  setTimeout("Effect.toggle('"+mainAreaLoading+"');", 1000);
	}

	function loadContent(id, mainAreaInternal, mainAreaLoading, module, template) {
	  startLoading(mainAreaInternal, mainAreaLoading);
	  new Ajax.Updater(mainAreaInternal, '/modules/'+ module +'.php', {method: 'post', postBody:'doc='+ id +'&tpl='+ template +''});
	  finishLoading(mainAreaInternal, mainAreaLoading);
	}

	function switchRollerButton(buttonsArray, buttonPrefix, button) {
		//alert(''+button_on+'');
		buttonON = buttonPrefix+button;
		for (var i = 0; i < buttonsArray.length; i++) {	
			//alert("off: "+buttonsArray[i]);
			document.getElementById(buttonsArray[i]).className='off';
		}
		document.getElementById(buttonON).className='on';
	}


	function nextArrElem(myArray, buttonPrefix, valueAktElem) {
		var indexAktElem=myArray.indexOf(buttonPrefix+valueAktElem);
		if (indexAktElem < myArray.length-1)
			valueNextElem= myArray[indexAktElem+1]
		else
			valueNextElem= myArray[0]
		
		arrIDs=valueNextElem.split('_');
		return(arrIDs[1])	
	}

	function prevArrElem(myArray, buttonPrefix, valueAktElem) {
		var indexAktElem=myArray.indexOf(buttonPrefix+valueAktElem);
		if (indexAktElem > 0)
			//return myArray[indexAktElem-1]
			valuePrevElem= myArray[indexAktElem-1]
		else
			valuePrevElem= myArray[myArray.length-1]
		
		arrIDs=valuePrevElem.split('_');
		//alert(' prev: '+  arrIDs[1])	
		return(arrIDs[1])	
		
	}
	
	
	
	function chContent(itemID, blokInternal, blokLoading, module, tpl, arr, buttonPrefix, arrowNextID, arrowPrevID) {
		
		loadContent(itemID, blokInternal, blokLoading, module, tpl); 
		switchRollerButton(arr, buttonPrefix, itemID); 
		prev=prevArrElem(arr, buttonPrefix, itemID);		
		next=nextArrElem(arr, buttonPrefix, itemID); 
		
		document.getElementById(arrowPrevID).onclick=function(){ chContent(prev, blokInternal, blokLoading, module, tpl, arr, buttonPrefix, arrowNextID, arrowPrevID)};
		document.getElementById(arrowNextID).onclick=function(){ chContent(next, blokInternal, blokLoading, module, tpl, arr, buttonPrefix, arrowNextID, arrowPrevID)};
		
	}