# Failure of Success Criterion 2.2.2 due to a script that causes a blink effect without a mechanism to stop the blinking at 5 seconds or less

ID: F50

Technology: failures

Type: Failure

## When to Use

Technologies that support script-controlled blinking of content.

## Description

Scripts can be used to blink content by toggling the content's visibility on and off at regular intervals. It is a failure for the script not to include a mechanism to stop the blinking at 5 seconds or earlier. See Using scripts to control blinking and stop it in five seconds or less for information about how to modify the technique to stop the blinking.

## Examples

The following example uses script to blink content, but the blink continues indefinitely rather than stopping after five seconds.

    <script>
      // blink "on" state
      function show(){
          document.getElementById("blink1").style.visibility = "visible";
          settime-out("hide()", 450);
       }

       // blink "off" state
       function hide(){
          document.getElementById("blink1").style.visibility = "hidden";
          settime-out("show()", 450);
       }

       // kick it off
       show();
    </script>
    ...
    <span id="blink1">This content will blink</span>

## Tests

### Procedure

For each instance of blinking content:

1. Determine if the blinking stops in 5 seconds or less.

### Expected Results

If #1 is false, then the content fails the Success Criterion.

## Related Techniques

- SCR22