<script type="text/javascript">
document.write("The new window's name is: " + myWindow.name)
<script type="text/javascript">
myWindow=window.open('','MyName','width=200,height=100')
myWindow.document.write("This is 'myWindow'")
<input type="button" value="What's the name of 'myWindow'?" onclick="checkWin()">