function calc_prop(axis) {
  if(document.forms[0].proportional.checked==false) return;
  orig_prop = $x_size$/$y_size$;
  if(axis=='x') document.forms[0].y_size.value 
    = Math.round(document.forms[0].x_size.value/orig_prop);
  if(axis=='y') document.forms[0].x_size.value 
    = Math.round(document.forms[0].y_size.value*orig_prop);
}

function confirmDelete(delhref) {
  if (confirm("Wirklich löschen?")) {
      document.location=delhref;
  }
}