function changeEmail(element) {

var name = document.getElementById(element).href;
var ergaenzung = '@fernuni-hagen.de';
var vollstaendig = '';

if (name.indexOf('@') == -1) {

   var name_array = name.split(';');

   for (var i = 0; i < name_array.length; i++) {

      vollstaendig = vollstaendig + name_array[i] + ergaenzung + ';';

   }

   document.getElementById(element).href = vollstaendig;

} // end if

return(true);
}