function changeClassName(control, classNameDefault, classNameChanged)
    {
	    if(aux2 != null)
	    {
		    aux2.className = classNameDefault;
		    control.className = classNameChanged;
	    }
	    else
		    control.className = classNameChanged;
			
	    aux2 = control;
    }
	    
	function changeColor(control)
	{
		if(aux != null)
		{
		    if(control.className == 'faq_header_changed') {
		        control.className = 'faq_header';
		    }else {
			    aux.className = 'faq_header';
			    control.className = 'faq_header_changed';
			}
		}
		else
		{
			control.className = 'faq_header_changed';
		}	
		aux = control;
	}
	
	function loadEvents() {
		var btn_1 = document.getElementById('btn_1');
		var btn_2 = document.getElementById('btn_2');
		var btn_3 = document.getElementById('btn_3');
		var menu_contenteiner_1 = document.getElementById('menu_contenteiner_1');
		var menu_contenteiner_2 = document.getElementById('menu_contenteiner_2');
		var menu_contenteiner_3 = document.getElementById('menu_contenteiner_3');
		
		var container = document.getElementById('container');
		
		btn_1.onclick = function () { 
							menu_contenteiner_1.style.visibility='visible';
							menu_contenteiner_2.style.visibility='hidden';
							menu_contenteiner_3.style.visibility='hidden';
						};				
		btn_2.onclick = function () { 
							menu_contenteiner_1.style.visibility='hidden';
							menu_contenteiner_2.style.visibility='visible';
							menu_contenteiner_3.style.visibility='hidden';
						};
		btn_3.onclick = function () { 
							menu_contenteiner_1.style.visibility='hidden';
							menu_contenteiner_2.style.visibility='hidden';
							menu_contenteiner_3.style.visibility='visible';
						};

		document.getElementById('content').onmousedown = function () { 
							menu_contenteiner_1.style.visibility='hidden';
							menu_contenteiner_2.style.visibility='hidden';
							menu_contenteiner_3.style.visibility='hidden';
						};
		document.getElementById('left').onmousedown = function () { 
							menu_contenteiner_1.style.visibility='hidden';
							menu_contenteiner_2.style.visibility='hidden';
							menu_contenteiner_3.style.visibility='hidden';
						};
    }