CODE EXAMPLE FOR JAVASCRIPT

open new window in java script

<script type="text/javascript">
var windowObjectReference = null; // global variable
var PreviousUrl; /* global variable that will store the
                    url currently in the secondary window */

function openRequestedSinglePopup(url) {
  if(windowObjectReference == null || windowObjectReference.closed) {
    windowObjectReference = window.open(url, "SingleSecondaryWindowName",
         "resizable,scrollbars,status");
  } else if(PreviousUrl != url) {
    windowObjectReference = window.open(url, "SingleSecondaryWindowName",
      "resizable=yes,scrollbars=yes,status=yes");
    /* if the resource to load is different,
       then we load it in the already opened secondary window and then
       we bring such window back on top/in front of its parent window. */
    windowObjectReference.focus();
  } else {
    windowObjectReference.focus();
  };

  PreviousUrl = url;
  /* explanation: we store the current url in order to compare url
     in the event of another call of this function. */
}
</script>

(...)

<p><a
 href="http://www.spreadfirefox.com/"
 target="SingleSecondaryWindowName"
 onclick="openRequestedSinglePopup(this.href); return false;"
 title="This link will create a new window or will re-use an already opened one"
>Promote Firefox adoption</a></p>

<p><a
 href="https://www.mozilla.org/support/firefox/faq"
 target="SingleSecondaryWindowName"
 onclick="openRequestedSinglePopup(this.href); return false;"
 title="This link will create a new window or will re-use an already opened one"
>Firefox FAQ</a></p>