How to return json from php with ajax call

Hello,

Im totally new to PHP. How do I return the json generated from the ajax call.

Ive seen numerous examples, but they only show tables and such being generated in while loops with echo statements. How do I return the entire json response back to the Ext.ajax in one chunk?

I used to code on the AS/400 and it had another way of doing it.

Sorry to ask such a simple question, but Im not familiar enough with PHP yet?

Thank You

How to return json from php with ajax call