How to open multiple links in new tabs, using javascript

I wanted to click a button, and have several new browser tabs open to specific websites.

This seems to work in Firefox 3.0.19, but not in IE8.

Any suggestions on a solution for both browsers?

<script language="javascript">
window.open('http://www...', '1 _newtab');
window.open('http://www...', '2 _newtab');
window.open('http://www...', '3 _newtab');
</script>