/* Check / Uncheck all checkboxex in a form with a given name */

function checkboxes_change(form_name,box_name){
  with(document.forms[form_name]){
    for(var counter=0;counter<elements.length;counter++) {
      if(elements[counter].type=='checkbox'&&elements[counter].name==box_name+'[]')
        if(elements[counter].checked==false)
          elements[counter].checked=true;
        else
          elements[counter].checked=false;
    }
  }
}

/* click a button in a form */

function btn_click(form,button){
  document.forms[form].elements[button].click();
}