And so that you don't go home empty handed, here's a function that does it (remember to put this in the head section:
function openBrWindow (theURL,winName,features)
{
window.open(theURL,winName,features);
}
You can then put something like:
onClick="openBrWindow('popup/help_general.htm','Help','scrollbars=yes,width=450'
Inside your link tag.