xml file formatting in metro style app.

i want to write some data in XML file using metro style app (.Net Framework 4.5).
 
here is the code which i have written and it works fine but problem is that the whole string is being written in s single line instead of XML text formatting. Therefore i can't read it properly. Every time i need to reformat the newly added data to understand it properly.
 
Here is the code i have written :
 

        Dim f As New FolderPicker
        f.SuggestedStartLocation = PickerLocationId.DocumentsLibrary
        f.ViewMode = PickerViewMode.Thumbnail
        f.FileTypeFilter.Add("*")
        Dim folder As StorageFolder = Await f.PickSingleFolderAsync
 
        Dim rootEle As XmlElement
 
        Dim file As StorageFile = Nothing
 
        file = Await folder.CreateFileAsync("demoXML.xml", CreationCollisionOption.ReplaceExisting)
 
        rootEle = doc.CreateElement("files_tbl")
        doc.AppendChild(rootEle)
 
        Dim ele As XmlElement
        ele = doc.CreateElement("files")
        rootEle.AppendChild(ele)
 
        Dim otherEle As XmlElement
        otherEle = doc.CreateElement("field-1")
        otherEle.InnerText = "data-1"
        ele.AppendChild(otherEle)
 
        otherEle = doc.CreateElement("field-2")
        otherEle.InnerText = "data-2"
        ele.AppendChild(otherEle)
 
        Await doc.SaveToFileAsync(file)