post = function(target,event) {
    var form = document.forms[0];
    form.action = target;
    if (form.event) form.event.value = event;
    form.submit();
  }

  ask = function(question) {
    return confirm(question);
  }

 chimg = function(image) {
   x = document.getElementById(image);
   x.src = (x.src.indexOf('_on')>0) ? x.src.replace(/_on/,"_off") : x.src.replace(/_off/,"_on");
 }