OK this is now working WOW thank you very much.
BUT it now leaves another unexpected issue.
As you will see in the screenshot I have take when I call the file directly using [www. sitename.com/ loan-calculator. php ] the calculator works exactly as it should.
Now on my website the first box now shows up (thanks to you) but when I click on "calculate" it doesn't work.
Any thoughts as to why please.