function IsEmailValid(oEmail)
{
  email = oEmail.value
  r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)")
  r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$")
  return (!r1.test(email) && r2.test(email))
}