moving file from child window to parent window

[droidus]

As you can probably tell by my title, I am trying to move a file from a child window, to parent window. Here is my code:

<script type="text/javascript">
function post_value(){
	window.opener.document.parentForm.$("parent").val() = document.childForm.$("child").val();
	self.close();
}
</script>
<form name="childForm" method='post' action='' id="childForm">
<table border=0 cellpadding=0 cellspacing=0 width=250>
<tr><td align="center"> Your name<input type="text" name="child" id="child" value='hello!'> 
<input type='submit' value='Submit' onClick="javascript: post_value();">
</td></tr>
</table>
</form>

and

<form method='post' action='' name='parentForm' id="parentForm">
  <a href="javascript:void(0);" NAME="A window" style="color:#000000;" title="A title" 
onClick='javascript: window=window.open("files.php","Ratting",
"width=550,height=170,left=150,top=200,toolbar=1,status=1");'>Link to child window</a> 
  <input type='text' name='parent' id="parent">
  </form>

When I click on the button in the child window, nothing happens. What's going on here?