function callout(id,visible) {
  if (visible) {
    // get position of cursor:
    // setcallout position to position of cursor
    document.getElementById("c-"+id).style.display = "block";
    document.getElementById("t-"+id).style.display = "none";
  } else {
    document.getElementById("c-"+id).style.display = "none";
    document.getElementById("t-"+id).style.display = "block";
  }
  return (true);
}

function togglewc(id) {
    var wordcloud = document.getElementById(id+"wordcloud");
    var link = document.getElementById(id+"link");
    if (wordcloud.style.display == "block") {
	wordcloud.style.display = "none";
	link.innerHTML = " Show ";
    } else {
	wordcloud.style.display = "block";
	link.innerHTML = " Hide ";
    }
    return (false);
}

//function verify_login() {
  // first check that userid and password are not empty
  // find js.sample code for json-communication...
  // then make call to twitter.com/verify_credentials.json
  // if ok (return code 200)
//  return true;
  // if not ok (return code 401)
//  return false; 
// }