//checks all DataGrid CheckBoxes with the given name with the given value
function ToggleAllCheckBoxes(aspCheckBoxID, checkVal) {
  re = new RegExp(':' + aspCheckBoxID + '$')  //generated control name starts with a colon
  for(i = 0; i < document.forms[0].elements.length; i++) {
    elm = document.forms[0].elements[i]
    if (elm.type == 'checkbox')
      elm.checked = checkVal
  }
}