If the submitted form lacks a required field, Interchange will display an error page. The default location is special_pages/needfield.html. To create this page, type the following text and save it as special_pages/needfield.html.
[include top] [include left] <p>The following information was not given:</p> <p><b>[error all=1 show_var=1 show_error=1 joiner='<br>']</b></p> <p>Please go back to the [page checkout]checkout page</a> and fill out the form properly.</p> [include bottom]
The [error] tag is the most important tag on this page. The all parameter tells the tag to iterate through all of the errors reported from the failed verification, and the show_var parameter indicates that the failed variable name should be displayed. For example, if the first name was left empty, fname would be shown. The show_error parameter displays the actual error for the variable. The joiner parameter inserts an HTML <br> tag between each error message, so each error is displayed on its own line. In more complex configurations, the [error] tag can be even more expressive.