Multiply values from a cell with jquery

Multiply values from a cell with jquery

My problem is that I have a table where I show products and costs, then when I entry the amount other cell be updated with the overall

for example

product price amount overall
eggs 100 300

The amount is entried for the user, it's a textfield

for example I have this code, but doesn't work good

$('#tabla tr td').click(function(){   
           var precio = $(this).text();
           var tr = $('#tabla tr').parent().parent();
           var cantidad=$("td:eq(2)", tr).text();
               var total=precio*cantidad;
    });

See this page -> http://www.mercadodeplaza.com/