How to make my form auto and open after 15 seconds.

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<script language="JavaScript">
var delayseconds = 15;
    function pause() {
    myTimer = setTimeout('whatToDo()', delayseconds * 1000)
    }
   function whatToDo() {
document.getElementById('lightboxdelay').click();
    }
window.onload = pause;
</script>

This question was answered at the following link below:

http://www.jotform.com/answers/714162-Auto-open-the-lightbox-form-after-15-seconds