Feature request - tax item

[AndrewPixel]

I've only used your invoice maker for a minutes but for me to use it also needs to be able to automatically add GST (a goods and service tax) to all subtotals. The current rate is Australia is 10%. and I don't really want to manually add all the items in an invoice and to then add GST as another item. The GUI would be:

[check box] Add tax [text field label] GST [number field] % rate [number field] current sub total

Still it's a nice web app.