How to delete an element from an xml

Question

please help me
how to delete an selected element from an xml
and my xml is

  <?xml version="1.0" encoding="UTF-8" ?>

- <Doctors>

  <DoctorName>3</DoctorName>

  <DoctorName>4</DoctorName>

  <DoctorName>Doctor1</DoctorName>

  <DoctorName>2</DoctorName>

  </Doctors>

when i selected "Doctor1" from a dropdownlist, it will be deleted from xml.
please help to do this.