Set Checkbox Value with JS

    // reset whole checkbox value to true/false
    function SetValues(Form, CheckBox, Value){
      var objCheckBoxes = document.forms[Form].elements[CheckBox];
      var countCheckBoxes = objCheckBoxes.length;
      for(var i = 0; i < countCheckBoxes; i++){
        objCheckBoxes[i].checked = Value;
        objCheckBoxes[i].value = Value;
      }
    }