$(document).ready(function(){
  $(":text").labelify({
    labelledClass: "label"
  });
});

function selectAll(checked){
  $("INPUT[type='checkbox']").attr('checked', checked);
}

function resizeText(multiplier) {
  var element = document.getElementById("content")
  if (element.style.fontSize == "") {
    element.style.fontSize = "1.0em";
  }
  element.style.fontSize = parseFloat(element.style.fontSize) + (multiplier * 0.2) + "em";
}

function handleArrowKeys(evt){
  evt = (evt) ? evt : ((window.event) ? event : null);
  var leftArrow = 37;
  var rightArrow = 39;
  var plusKey = 107;
  var minusKey = 109;
  if (evt) {
    switch (evt.keyCode) {
      case leftArrow:
        gotoAddress("previous_page")
        break;
      case rightArrow:
        gotoAddress("next_page")
        break;
      case plusKey:
        resizeText("1");
        break;
      case minusKey:
        resizeText("-1");
        break;
    }
  }
}

function gotoAddress(addr){
  var address = document.getElementById(addr);
  if (address == null){
    return null;
  }
  else{
    location.replace(address.getAttribute("href"));
  }
}

function focus_next_element(element_id, next_element_id){
  var element = document.getElementById(element_id);
  if (element.value.length == parseInt(element.getAttribute('maxlength'))){
    next_element = document.getElementById(next_element_id);
    if (next_element.value.length == 0){
      next_element.focus();
    }
  }
}