Looking for an answer for best code.

[RNK Concepts]

Hello,

I have an online form that I am building in PHP. Basically, I need the user to fill out certain form fields, and when those fields are completed, I need to automatically post the data in those fields into fields within an equation that is visible on screen. The following picture shows the circled area and where it should appear in the equation.



I am currently trying to use $POST data ... But I'm thinking that ajax would work much better ... Any ideas?

Any links to the code that may help is greatly appreciated!

Thanks.