function go_tab(tab) {
	switch (tab) {	
		case "measure" :
			document.all.measure_tab.style.display="";
			document.all.car_tab.style.display="none";
			
			document.all.measure.src = measureon.src;
			document.all.car.src = caroff.src;

			break;		
		case "car" :
			document.all.measure_tab.style.display="none";
			document.all.car_tab.style.display="";
			
			document.all.measure.src = measureoff.src;
			document.all.car.src = caron.src;

			break;	
	}

}

function go_tab_eng(tab) {
	switch (tab) {	
		case "overview" :
			document.all.overview_tab.style.display="";
			document.all.effect_tab.style.display="none";
			
			document.all.overview.src = overviewon.src;
			document.all.effect.src = effectoff.src;

			break;	
		case "effect" :
			document.all.overview_tab.style.display="none";
			document.all.effect_tab.style.display="";

			
			document.all.overview.src = overviewoff.src;
			document.all.effect.src = effecton.src;

			break;		
	}

}