Dynamically adding URLs to buttons

I have an XML file that has a large group of buttons. (ex below)
code:
<unitedstates>

  <state name="WA">

    <enabled>1</enabled>

    <bordercolor>3F3F3F</bordercolor>

    <color>336699</color>

    <url>http://www.hotmail.com</url>

  </state>

  <state name="OR">

    <enabled>1</enabled>

    <bordercolor>3F3F3F</bordercolor>

    <color>336699</color>

    <url>http://www.gmail.com</url>

  </state>

</unitedstates>
I want to be able to dynamically have each of those buttons go to the URL I specified in the <url></url> tag.

This is the code that I am trying to do as I loop through the XML file, but it's assigning it onrelease. I want to assign it at the beginning.
code:
for(var i = 0; i < xmlDoc_xml.firstChild.childNodes.length; i++){

  var strURL = xmlDoc_xml.firstChild.childNodes[i].childNodes[3].firstChild.nodeValue;

  eval(stateName).onRelease = function(){

    trace(strURL);

    getURL(strURL, "_self");

  }

}
the problem with this is that it assigns the last URL in the XML file to the every button I click on. So in this instance, the WA button AND the OR button will both go to gmail.com because that's the last one it was assigned to.

How do I add the right URL to the right button in that loop and have it stick?

Thanks.