Form box, different result depending on input

[Duke Will]

How can I do this? Say, I have an input box, where the visitor types in an answer. Like,

"How much is your pledge (in dollars)?"

Depending on what they input and then click SUBMIT or whatever, it would display what they get. Ideally, right there on that page or I guess it could open a new page. Rules...

If the answer is 1 to 10, they get A
If the answer is 11 to 19, they get A and B
If the answer is 20 to 49, they get A, B and C
If the answer is 50 or more, they get A, B, C, D

[Bootsman123]

You have to lay your hands on a programming language. If you want it done right on the page, you can use Javascript. If you don't mind opening a new window or reloading the page, then you can use, CGI, PHP, ASP etc.