Website builder

I am using Yahoo site builder to create an online store, when i inert the Store Tags on my website, which option should i pick, allow me to add a text box kind of thing, so it can let my customer leave some message to me, something like the “text area” in the form, but i want it inside the store tag box, so when the customer click “order now” it will showup with the message at the next shopping cart page within the “options” area -thank you