i need to load the json dynamically without knowing the fields name..

i need to load the json dynamically without knowing the fields name..

i need to load the json dynamically without knowing the fields name..
how can i do it?

as well: i could get the fields name from the server..
but than how to make the call 

so instead of 
j[ind].ID

i will call 
var fieldName = j[ind][0].key,
    fieldVal = j[ind][0].val;

or

ver val = j[ind]["theKay"]