Insert an item in javascript object at perticular position : I have an object in javascript whose structure is like

    Comment : "Test" 
    DefaultWt : "0" 
    Label : "O" 
    Wt : "1680"
    Aft: "0" 
    lat : "0"
    lon: "0" 
    Button : "false"
    position : "0"

I want to add an element after button and before position. How to do it?