I set up the attached spreadsheet (in both MS and OOo format) just for keeping track of salaries and payroll liabilities. I thought that it might be useful for some people. It is based on the 2007/08 tax rates
BE CAREFUL and check that everything is correct before going ahead and basing your payments on this spreadsheet. It is provided "as is" and may contain errors. I take no responsibility for any liabilities which you may incur making use of this spreadsheet. I am not an accountant or a financial advisor. If you have a bad hair day as a result of this info, don't phone me.
Other than that, I think it is pretty much okay You should be able to easily modify it to suit your particular situation. Please let me know if you do find any errors, and I'll correct them and repost.