Java Script - Json - Simple Request

I have a JSON file with nested values. I need a JavaScript code be able to read specific values in JSON file. --------------------------------------------- var request = new XMLHttpRequest(); [login to view URL]('GET', '/json/[login to view URL]', true); [login to view URL] = 'ratesJSON'; [login to view URL] = function() { var ratesJSON = [login to view URL]; [login to view URL](ratesJSON); /* At this point i need to get a specific values from JSON file. From zaymer -> 13000 -> 1 -> 0.1 ! - this is a value i need to get. and i need to make it with variables in Java script. ratesJSON["offer"]["amount"]["length"] so i need a function and each time get what i need. function getvalues (offer, amount, length){ //function happening here. and in the end var rate = ratesJSON["offer"]["amount"]["length"]. } /* }; [login to view URL](); --------------------------------------------- { "zaymer": { "13000": { "1": 0.1, "2": 0.1, "3": 0.1, "4": 0.1 }, "14000": { "1": 0.1, "2": 0.1, "3": 0.1, "4": 0.1 } }, "migcredit": { "13000": { "1": 0.1, "2": 0.1, "3": 0.1, "4": 0.1 }, "14000": { "1": 0.1, "2": 0.1, "3": 0.1, "4": 0.1 } } }