// verifies that thee email address provided is correct.

var reEmail = /^.+\@.+\..+$/
var defaultEmptyOK = false


function isEmpty(s) { 
  return ((s == null) || (s.length == 0))
}


function isEmail (s){
  if (isEmpty(s)) 
    if (isEmail.arguments.length == 1) return defaultEmptyOK;
    else return (isEmail.arguments[1] == true);
    
  else {
    return reEmail.test(s)
  }
}