Create JSON from Dynamic form

I'm creating a dynamic form. Which has drag and drop feature. When Admin has completed the form creation,I have to save form details in Db.

Fiddle link for Form Generation

I don't know from where to start or how to traverse the form to save in json format.

I was to save Json format like this

var formDetails = [

        {
            "type":"textbox",
            "label":"Please enter your name",
            "id":"txt-1465133974748"
        },
        {
            "type":"select",
            "label":"Please Select Option",
            "id":"select-1865133974748",
            "fieldOptionDetails":[
            {
                "fieldLabel":"Option 1",
                "fieldValue":"1"
            },
            {
                "fieldLabel":"Option 2",
                "fieldValue":"2"
            }]
        }];