// Author:Muhammad neamul Mowla Pinju
function change(id){
	if(id=='nav_a' || !id)
	{
		document.getElementById('cart_1').style.display="block";
		document.getElementById('cart_2').style.display="none";
		document.getElementById('cart_3').style.display="none";
		document.getElementById('cart_4').style.display="none";
		document.getElementById('dph').style.display="block";
		
		document.getElementById('nav_a').className ='slc_nav';
		document.getElementById('nav_a').style.background ='url(images/cart_tab_sl1.jpg) no-repeat  4px 6px';
		document.getElementById('nav_b').className ='ns_nav';
		document.getElementById('nav_c').className ='ns_nav';
		document.getElementById('nav_d').className ='ns_nav';
		
		document.getElementById('nav_a').style.cursor="pointer";
		document.getElementById('nav_b').style.cursor="pointer";
		document.getElementById('nav_c').style.cursor="default";
		document.getElementById('nav_d').style.cursor="default";		
		
	}
	else{
		document.getElementById('nav_a').style.background ='url(images/cart_tab1.jpg) no-repeat  4px 6px';
			
		}
	
	
	if(id=='nav_b')
	{
		document.getElementById('cart_1').style.display="none";
		document.getElementById('cart_2').style.display="block";
		document.getElementById('cart_3').style.display="none";
		document.getElementById('cart_4').style.display="none";
		document.getElementById('dph').style.display="block";
		
		document.getElementById('nav_a').className ='ns_nav';
		document.getElementById('nav_b').className ='slc_nav';
		document.getElementById('nav_b').style.background ='url(images/cart_tab_sl2.jpg) no-repeat  4px 6px';
		document.getElementById('nav_c').className ='ns_nav';
		document.getElementById('nav_d').className ='ns_nav';

		document.getElementById('nav_a').style.cursor="pointer";
		document.getElementById('nav_b').style.cursor="pointer";
		document.getElementById('nav_c').style.cursor="pointer";
		document.getElementById('nav_d').style.cursor="default";			
	}
	
	else{
		document.getElementById('nav_b').style.background ='url(images/cart_tab2.jpg) no-repeat  4px 6px';
			
		}
	
	if(id=='nav_c')
	{
	  
		document.getElementById('cart_1').style.display="none";
		document.getElementById('cart_2').style.display="none";
		document.getElementById('cart_3').style.display="block";
		document.getElementById('cart_4').style.display="none";
		document.getElementById('dph').style.display="none";
		
		document.getElementById('nav_a').className ='ns_nav';
		document.getElementById('nav_b').className ='ns_nav';
		document.getElementById('nav_c').className ='slc_nav';
		document.getElementById('nav_c').style.background ='url(images/cart_tab_sl3.jpg) no-repeat  4px 6px';
		document.getElementById('nav_d').className ='ns_nav';

		document.getElementById('nav_a').style.cursor="default";
		document.getElementById('nav_b').style.cursor="pointer";
		document.getElementById('nav_c').style.cursor="pointer";
		document.getElementById('nav_d').style.cursor="default";	
	}
	
	else{
		document.getElementById('nav_c').style.background ='url(images/cart_tab3.jpg) no-repeat  4px 6px';
			
		}
	
	if(id=='nav_d')
	{
		document.getElementById('cart_1').style.display="none";
		document.getElementById('cart_2').style.display="none";
		document.getElementById('cart_3').style.display="none";
		document.getElementById('cart_4').style.display="block";
		document.getElementById('dph').style.display="none";
		
		document.getElementById('nav_a').className ='ns_nav';
		document.getElementById('nav_b').className ='ns_nav';
		document.getElementById('nav_c').className ='ns_nav';
		document.getElementById('nav_d').className ='slc_nav';
		document.getElementById('nav_d').style.background ='url(images/cart_tab_sl4.jpg) no-repeat  4px 6px';
		
	}
	
	else{
		document.getElementById('nav_d').style.background ='url(images/cart_tab4.jpg) no-repeat  4px 6px';
			
		}
	
	
	

}