function show_div(aan, uit, z){

		div_aan = "cont_" + aan;
		div_uit = "cont_" + uit;
		tab_aan = "tab_" + aan;
		tab_uit = "tab_" + uit;
		
		//alert(div_aan + div_uit + tab_aan + tab_uit);
		cont_uit = document.getElementById(div_uit);
		cont_aan = document.getElementById(div_aan);
		tabbl_uit = document.getElementById(tab_uit);
		tabbl_aan = document.getElementById(tab_aan);
		if(z == 'r'){
		if(tabbl_aan.style.backgroundImage == "url(img/tab_o.gif)"){
		tabbl_aan.style.backgroundImage = "url(img/tab_a.gif)";
		tabbl_uit.style.backgroundImage = "url(img/tab_u.gif)";
		}
		}
				if(z == 'l'){
		if(tabbl_aan.style.backgroundImage == "url(img/tab_o.gif)"){
		tabbl_aan.style.backgroundImage = "url(img/tab_a.gif)";
		tabbl_uit.style.backgroundImage = "url(img/tab_u.gif)";
		}
		}
		cont_uit.style.display = "none";
		cont_aan.style.display = "block";
	}
	function set_div(aan, uit, z){

		div_aan = "cont_" + aan;
		div_uit = "cont_" + uit;
		tab_aan = "tab_" + aan;
		tab_uit = "tab_" + uit;
		
		//alert(div_aan + div_uit + tab_aan + tab_uit);
		cont_uit = document.getElementById(div_uit);
		cont_aan = document.getElementById(div_aan);
		tabbl_uit = document.getElementById(tab_uit);
		tabbl_aan = document.getElementById(tab_aan);
		if(z == 'r'){

		tabbl_aan.style.backgroundImage = "url(img/tab_a.gif)";
		tabbl_uit.style.backgroundImage = "url(img/tab_u.gif)";
	
		}
		cont_uit.style.display = "none";
		cont_aan.style.display = "block";
	}
function show_tab_over(tab_div, z){
		
		tab_div = document.getElementById(tab_div);
		if(z == 'r'){
		if(tab_div.style.backgroundImage == "url(img/tab_u.gif)"){
		tab_div.style.backgroundImage = "url(img/tab_o.gif)";
		}
		}
				if(z == 'l'){
		if(tab_div.style.backgroundImage == "url(img/tab_u.gif)"){
		tab_div.style.backgroundImage = "url(img/tab_o.gif)";
		}
		}
	}
function hide_tab_out(tab_div, z){
		tab_div = document.getElementById(tab_div);
		if(z == 'r'){
		if(tab_div.style.backgroundImage == "url(img/tab_o.gif)"){
		tab_div.style.backgroundImage = "url(img/tab_u.gif)";
		}
		}
				if(z == 'l'){
		if(tab_div.style.backgroundImage == "url(img/tab_o.gif)"){
		tab_div.style.backgroundImage = "url(img/tab_u.gif)";
		}
		}
	}