function selCheckBox(chk_val,strProduct,strCost)
		{
			document.getElementById('box_'+chk_val).checked=true;	
			document.getElementById(chk_val).style.display="none";
			document.getElementById('chk_'+chk_val).style.display="block";
			
			document.getElementById(strProduct).style.display="block";
			
			var total_int = eval(strCost)+eval($("#total_int").html());
			var total_str = '$'+total_int;
			$("#total_str").html(total_str);
			$("#total_int").html(total_int);			

		}
		function unselCheckBox(chk_val,strProduct,strCost)
		{
			document.getElementById('box_'+chk_val).checked=false;	
			document.getElementById(chk_val).style.display="block";
			document.getElementById('chk_'+chk_val).style.display="none";
			
			document.getElementById(strProduct).style.display="none";
			
			var total_int =eval($("#total_int").html())-eval(strCost);
			var total_str = '$'+total_int;
			$("#total_str").html(total_str);
			$("#total_int").html(total_int);
			
		}