function selectAll() {
 d = document.act_form;
 for (i = 0; i < d.elements.length; i++) {
   if (d.elements[i].type == "checkbox") {
     d.elements[i].checked = true;
   }
 }
}

function deselectAll() {
 d = document.act_form;
 for (i = 0; i < d.elements.length; i++) {
   if (d.elements[i].type == "checkbox") {
     d.elements[i].checked = false;
   }
 }
}