[FMX] paragraph quiz

I had an idea for a quiz in flash.

There would be a input text field that contains a paragraph with multiple spelling errors.
The user would correct the errors and then check their answer. The quiz would assess the user and let them know what parts of the paragraph they got correct or incorrect.

My question: How would you check the multiple errors in the paragraph via action script?

Thanks in advance Im not too good at this stuff.