/* restore the default value of an input field */ 
function removeDefault( O, text ) {
  if ( O.value == text )
    O.value = "";
  else if ( O.value == 0 ) // for konquerer+safari
    O.value = "";
}

/* set a default value for an input field */ 
function setDefault( O, text ) {
  if ( O != null && O.value == "" )
    O.value = text;
}