I am creating a web page where the user and select an item by clicking on the button. The details of the item selected will be displayed in a dropbox. At the moment I can get it to update the quantity if the user selects it again. The problem which I am having is, say if the user first click on btnBuy1 (details displayed in dropbox), then clicks on btnBuy2 (again, details are displayed), but when they click on btnBuy2 again , the details from btnBuy2 is updated but the details from btnBuy1 disappears.

Code:
			$("#btnBuy0").click(function()
			{
				if (!sessionStorage['quantity0'])
				{
					sessionStorage['quantity0'] = 1;
					$("#dropbox").append('<span id = "0"><img class = "thumb" src="../images/21_metoyou.jpg" />' + teddy[0].desc + ", Price £"
				 + teddy[0].price + ", Quantity: " + sessionStorage.getItem('quantity0') + "</span><br/>");

				}		 	
				else
				{
					sessionStorage['quantity0']++;
					$("#dropbox").html('<span id = "0"><img class = "thumb" src="../images/21_metoyou.jpg" />' + teddy[0].desc + ", Price £"
				 + teddy[0].price + ", Quantity: " + sessionStorage.getItem('quantity0') + "</span><br/>");

				}
				if (Modernizr.sessionstorage) 
				{  // check if the browser supports sessionStorage
  					myids.push(teddy[0].partnum); // add the current username to the myids array
 					sessionStorage["ids"]=JSON.stringify(myids); // convert it to a string and put into sessionStorage
				} 	
				else 
				{
			 	 // use cookies instead of sessionStorage
			 	}
			});
			$("#btnBuy1").click(function()
			{
				if (!sessionStorage['quantity1'])
				{
					sessionStorage['quantity1']=1;
					$("#dropbox").append('<span id = "1"><img class = "thumb" src="../images/birthday_metoyou.jpg" />' + teddy[1].desc + ", Price £"
				 + teddy[1].price + ", Quantity: " + sessionStorage.getItem('quantity1') + "</span><br/>");

				}
				else
				{
					sessionStorage['quantity1']++;
					$("#dropbox").html('<span id = "1"><img class = "thumb" src="../images/birthday_metoyou.jpg" />' + teddy[1].desc + ", Price £"
				 + teddy[1].price + ", Quantity: " + sessionStorage.getItem('quantity1') + "</span><br/>");

				}
				if (Modernizr.sessionstorage) 
				{  // check if the browser supports sessionStorage
			  		myids.push(teddy[1].partnum); // add the current username to the myids array
			 		sessionStorage["ids"]=JSON.stringify(myids); // convert it to a string and put into sessionStorage
				} 
				else 
				{
			 	 // use cookies instead of sessionStorage
			 	}
			});