How do I change the checkout default number?

When someone wants to checkout after they already added what they want to the cart there is a button with a box that has a 1 in it by default. If the customer clicks the button they end up with 2 quantity. I want the default to be zero so they get just 1 quantity. As you can see from the attached picture.

This is done when you are adding your products. you can also go back to your product, go to edit, then find the line:

Product Qty Minimum:

Set that to 0, and it will show 0 on the products page.

Don't do that ...

You cannot allow a minimum order of 0 ...

You would need to customize your template for the:
tpl_product_info_display.php

copy to your templates and overrides directory then adjust how this line is managed for the quantity:

    $the_button = PRODUCTS_ORDER_QTY_TEXT . '<input type="text" name="cart_quantity" value="' . (zen_get_buy_now_qty($_GET['products_id'])) . '" maxlength="6" size="4" /><br />' . zen_get_products_quantity_min_units_display((int)$_GET['products_id']) . '<br />' . zen_draw_hidden_field('products_id', (int)$_GET['products_id']) . zen_image_submit(BUTTON_IMAGE_IN_CART, BUTTON_IN_CART_ALT);

:oops: My bad. Sorry.

If you set the default quantity to 0, every single customer will have to enter a 1 in the box before clicking add to cart; if they don't notice this, they will add to cart and get nothing in the cart.

How many more frustrated customers will you get this way than customers who don't know that add to cart is not the same thing as checkout?

Is there another button supposed to be there with just Checkout instead of add to cart? I see no reason why the customer is asked to add more to the cart after he/she is done shopping. In my case I only see this one button with Add to cart on it.:dontgetit

How can the cart know when the customer is done shopping? It's impossible. The customer has to tell the cart they are done by pressing "Checkout" in the navigation (next to the "Shopping Cart" link). If this is a problem for your customers, you can make the checkout more prominent.

Okay I see now, this is only when the customer clicks on the shopping cart side box that he will see this. Is is possible to add a checkout button on this page by customisation? The checkout on the menu is not as obvious.

You can add a checkout button to your product info pages - find the code where it is used on the shopping cart page and copy that to tpl_product_info_display.php.

There is also a Checkout link by default in the header navbar (by Home Login) that will appear when there is something in the cart.