Javascript - read JSON Array without square brackets

So I got this JSON Object. And I would like to iterate throug all the Objects in nodes but the Objects the nodes Object is not formatet as an Array with []

I can access one after the other, if I know the name for example:

var X = Trend.L13

var node = X.nodes["AGENT.OBJECTS.House.SKL04_SK2.L13.Frost.AL01"]

But how do I iterate them?

var Trend = {


L13: {
    dataArchive: "datavalues",
    nodes: {

      "AGENT.OBJECTS.House.SKL04_SK2.L13.Frost.AL01": {
        visible: true,
        axis: "left",
        style: "Line",
        color: "#66AF31",
        linewidth: 1,
        nonstop: true,
        stairs: true,
        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.Frost.AL01",

        text: "Frost"
      },
      "AGENT.OBJECTS.House.SKL04_SK2.L13.TempZul.MT01": {
        visible: true,
        axis: "right",
        style: "Line",
        color: "#8701AF",
        linewidth: 1,
        nonstop: true,
        stairs: false,

        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.TempZul.MT01",
        text: "Temp ZUL"
      },
      "AGENT.OBJECTS.House.SKL04_SK2.L13.PuWrg.SS01": {
        visible: true,
        axis: "left",
        style: "Line",
        color: "#000",
        linewidth: 1,

        nonstop: true,
        stairs: true,
        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.PuWrg.SS01",
        text: "PuWRG"
      },
      "AGENT.OBJECTS.House.SKL04_SK2.L13.TempWrgVl.MT01": {
        visible: true,
        axis: "right",
        style: "Line",

        color: "#FF2511",
        linewidth: 1,
        nonstop: false,
        stairs: false,
        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.TempWrgVl.MT01",
        text: "Temp. WRG Vorlauf"
      },
      "AGENT.OBJECTS.House.SKL04_SK2.L13.TempZulNachWRG.MT01": {
        visible: true,

        axis: "right",
        style: "Line",
        color: "#F99602",
        linewidth: 1,
        nonstop: false,
        stairs: false,
        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.TempZulNachWRG.MT01",
        text: "Temp. ZUL nach WRG"
      },

      "AGENT.OBJECTS.House.SKL04_SK2.L13.VtWrg.SS01": {
        visible: true,
        axis: "left",
        style: "Line",
        color: "#A5184A",
        linewidth: 1,
        nonstop: false,
        stairs: true,
        configname: "L13",
        address: "AGENT.OBJECTS.House.SKL04_SK2.L13.VtWrg.SS01",

        text: "VT WRG"
      }
    },
    leftAxis: {
      visible: "1",
      autoScale: "1",
      min: -3.7,
      max: 37,
      description: "Linke Achse"
    },

    rightAxis: {
      visible: "1",
      autoScale: "0",
      min: 0,
      max: 40,
      description: "Rechte Achse"
    },
    time: {
      startTime: 1453010899798,
      endTime: 1453183699799,

      lastTime: "1",
      lastTimeValue: 2,
      lastTimeUnit: "86400"
    },
    newnodes: {}
  }
}