The future of the web goes probably in dedicated services that are distributed on the Internet and accessible from a webpage using Ajax technology.
ChemCalc is now accessible as a web service and in the following pages we will present some examples and also an explanation of how to implement them.
If you simply want to add a link to a window in order to generate the molecular formula you may just insert a code like:
<a href="http://www.chemcalc.org/analyse?mf=Et3N" target="_blank">Et3N</a>
In which you simply change the value of the molecular formula. You may check the result here