Question: I have this very simple Javascript to write on a text area when the link is clicked:

```
<head>
<script language="javascript" type="text/javascript">
    function addtext(text) {document.form.textarea.value = document.form.textarea.value+= text;}
    </script>
</head>

<body>
<form action="" method="" name="form">
   <textarea name="textarea" rows="" cols="" wrap="wrap"></textarea>
</form>
<a href="javascript:addtext('q');">q</a>
</body>

```

Now I want to up the ante.

What I want to do is have the form in another another window, and that when I click the link, I writes to a textarea in another window.

I'm not necessarily asking for the code because I realize this might be quite complicated. 

The question would be where to start, because I haven´t got a clue!!
(when I Google cross window or cross domain interaction with Javascript I don't really get anything useful).

So any help I can get, libraries, plugins or whatever might guide me in the right direction is more than appreciated.

Answer: 
Ok, I wrote you a sample you can check at <http://jsfiddle.net/zzdAL/>

```
$(document).ready(function()
                  {
                      popup = window.open("http://fiddle.jshell.net");
                      $("#input1").click(function() {
                          try {
                                popup.document.window.alert(1);
                          }
                          catch (e) { alert(e.message); }
                      });
                  }
                 );

```

It only runs an alert on the popup, but you can do whatever you want with the popup, assuming you have the necessary rights (needs to be the same domain I believe).

The most simple is to write a function in your popup and call it from the opener.
Probably it's too late, but here is an example of interaction: [window interaction](http://theopensourcery.com/jswin.htm)