last_tab = 'tab1';
		function show(layerName) { 
			document.getElementById(layerName).style.display = '';
			//return 'background-image:url(./images/ltab_blue.gif);';
		} 
		
		function hide(layerName) { 
			document.getElementById(layerName).style.display = 'none';
			//return 'background-image:url(./images/ltab_blue.gif);';
		}	
		function show_next(tab_name) {
			document.getElementById(last_tab).className = 'tab';
			var curr = document.getElementById(tab_name);
			curr.className='tab_hover';
			hide(last_tab+'_data');
			show(tab_name+'_data');
			last_tab=tab_name;
		}
		last_tab2 = 'tab21';
		function show2(layerName) { 
			document.getElementById(layerName).style.display = '';
		} 
		
		function hide2(layerName) { 
			document.getElementById(layerName).style.display = 'none';
		}	
		function show_next2(tab_name) {
			document.getElementById(last_tab2).className = 'tab2';
			var curr = document.getElementById(tab_name);
			curr.className='tab_hover2';
			hide2(last_tab2+'_data');
			show2(tab_name+'_data');
			last_tab2=tab_name;
		}