You have two options for canceling orders on our website.
Scroll down to the "My Orders and Trades" section on the main page. The first tab is the "Active orders" tab, where you can find the "Cancel" buttons on the right side of each order. To see your active orders on all markets, click trading pair on the head of the section (for example, BCH/ETH).
Another option to cancel an order is to proceed "My Orders" tab on the Reports page. There you can filter your active orders and push the "Cancel" button on the right of the order you wish to cancel.