<a href="javascript:void window.open('help.php', 'image', 'directories=no,location=no,menubar=no,personalbar=no,toolbar=no,status=no,scrollbars=yes,width=400,height=250');">
Read this for help</a>
Is that you need?
Sorry, edited:
help.php is the script that select the help from the database. You can write some like javascript... ('help.php?topid=login'...
if you want to diferenciate between some help. dependind on topid.