HTML coding to open link in new window

Hi

I am currently trying to add a link in the side bar.

I have used ethe Custom HTML widget.

I enter the coding below:

<a href="http://www.ajavachatsite.com" target="_blank">CHAT</a>

I click save, go to check it and it opens up in the forum page replacing the forum.

I go back into the settings and it has changed to:

<a href="http://www.ajavachatsite.com" rel="nofollow" class="external">CHAT</a>

Any ideas how I can provide a link for a java chat that will open a new window?? 

I have read the tutorial for the chatango but have a picky bunch that don't like chatango.