function changeImages() {
  for(var i=0;i<arguments.length;i+=2) {
    document[arguments[i]].src = arguments[i+1];
  }
}

function selectField(f) {
  f.select();
  f.focus();
}

function checkAll(frmName,checkStatus,chkName) {
  var lmax = document.forms[frmName].elements.length;
  var element;

  for (var lCounter=0; lCounter < lmax; lCounter++) {
    element = document.forms[frmName].elements[lCounter];

    if (chkName) {
      if (element.type == "checkbox" && element.name.match(chkName))
        element.checked = checkStatus;
    } 
    else {
      if (element.type == "checkbox")
        element.checked = checkStatus;
    }
  }     
}