Writing XML

First of all you have to add name space
Imports System.Xml

Dim textWriter As XmlTextWriter = New XmlTextWriter(Application.StartupPath & "\config.xml", Nothing)
' Opens the document
textWriter.WriteStartDocument()
' Write first element
textWriter.WriteStartElement("Projects")
'writing Sub Element
textWriter.WriteStartElement("Agency")
'Writing Value
textWriter.WriteString(txtAgencyName.Text.Trim())
textWriter.WriteEndElement()
textWriter.WriteStartElement("AgencyID")
textWriter.WriteString(txtAgencyId.Text.Trim())
textWriter.WriteEndElement()
' Write next element
textWriter.WriteStartElement("Project")
textWriter.WriteStartElement("Name", "")
textWriter.WriteString(IIf(option1.Checked = True, "Checked", "Not checked "))
textWriter.WriteEndElement()
textWriter.WriteEndElement()
' Ends the document.
textWriter.WriteEndDocument()
' close writer
textWriter.Close()