The proximate cause of the error is id is not submitted with the form. There may be an easier way that would eliminate the code that is presumably duplicated between index and buy/sell.

The button element has an attribute formaction that will override the action attribute of the form attribute.

The proximate cause of the error is id is not submitted with the form. There may be an easier way that would eliminate the code that is presumably duplicated between index and buy/sell.

The button element has an attribute formaction that will override the action attribute of the form element.