Implementation advice

When an error occurs:

  • prefix the <title> with "Error: "
  • show an error summary at the top of the page
  • move keyboard focus to the start of the summary to move keyboard focus, put tabindex="-1" on the containing div and use obj.focus()
  • ensure that the summary is announced to as many screen readers as possible use role="alert" on the containing div
  • use a heading at the top of the summary
  • associate the heading with the summary box use the ARIA attribute aria-labelledby on the containing div, so that screen readers will automatically announce the heading as soon as focus is moved to the div
  • link from the error list in the summary to the fields with errors
  • add a 5px red left border to the field with the error
  • show a red and bold error message between each question and field with an error
  • associate each error message with the corresponding field by adding it to the label (or legend)

Also consider using the aria-invalid attribute to programmatically indicate that a field has an error. The value of the aria-invalid attribute will vary depending on the type of error.