function MDN()
{
  var a, b, c, d, e;
  a = "nagaoka";
  b = "-ct";
  c = ".ac";
  d = ".jp";
  e = "@";
  document.write(e,a,b,c,d);
}

function MDSN()
{
  var a, b, c, d, e;
  a = "st.nagaoka";
  b = "-ct";
  c = ".ac";
  d = ".jp";
  e = "@";
  document.write(e,a,b,c,d);
}