blustar angel

how do i increase the quatity of an item when it is added again and again into my shopping cart table.there is only a button add to cart.there is no textfeild for quantitiy.
the code as of now i have retreives the items from database and add it into the shipping cart table. if i clik on it again and again the same item wil be shown again and again.

Java Code:

 DefaultTableModel model = (DefaultTableModel) 
tbl1.getModel();
            DefaultTableModel tm = (DefaultTableModel)

...