postMessage

by lquixada

HTML

<h4>This iframe is located on http://jsfiddle.net/lquixada/GueSN/</h4>    

<form>
  <input type="text" name="msg" placeholder="Message to send"/>
  <input type="button" value="send" onclick="sendMessage(this.form); return false;"/>
</form>

<script>
function sendMessage( form ) {
    var field = form.elements['msg'];
    
    window.parent.postMessage( field.value, "http://jsbin.com/" );
}
</script>