How to receive and read DTMF response in asterisk

how to receive DTMF response in asterisk?
while background() works, if we detect digits, i have to listen and show the digits result in web page.
to do this, what i have to do in asterisk?

https://wiki.asterisk.org/wiki/display/AST/Asterisk+18+Application_Read

If you read about the background() application, you will learn the secret.

Most of your questions over the last couple of weeks could be answered by reading a good book (‘Asterisk: The Future of Telephony’ for example. It may be a bit dated, but gives a good ‘background’) and working through the examples.

Having a greater understanding of Asterisk will help you choose appropriate solutions and trying examples will lead to a greater understanding of how things work.

For example, in your case where you want to ask a question a couple of times, maybe read() is a better choice than background().