How to simulate a click to make the current input lose its focus with JavaScript

Try using the blur event. If you're using jQuery there is a method you can call on the DOM object to raise this event. The blur() method should also work without jQuery.

http://docs.jquery.com/Events/blur

I would imagine using blur() would do the trick:

<script type="text/javascript">
    YAHOO.util.Event.onDOMReady(function() {
        document.getElementById("input").focus();    
        document.getElementById("input").blur();    
    });
</script>