// JavaScript Document
function zoomer(zoom) {
  var links = document.getElementsByTagName('a');
  var cells = document.getElementsByTagName('td');
  var ps = document.getElementsByTagName('p');
  var spans = document.getElementsByTagName('span');
  var fonts = document.getElementsByTagName('font');
  var divs = document.getElementsByTagName('div');
  for(var r = 0; r < links.length; r++){
    zoomElem(links[r], zoom);
  }
  for(var r = 0; r < cells.length; r++){
    zoomElem(cells[r], zoom);
  }
  for(var r = 0; r < ps.length; r++){
    zoomElem(ps[r], zoom);
  }
  for(var r = 0; r < spans.length; r++){
    zoomElem(spans[r], zoom);
  }
  for(var r = 0; r < fonts.length; r++){
    zoomElem(fonts[r], zoom);
  }
    for(var r = 0; r < divs.length; r++){
    zoomElem(divs[r], zoom);
  }
}

function zoomElem(elem, zoom) {
    if(window.getComputedStyle) {
      elem.style.fontSize = getZoom(window.getComputedStyle(elem, "" ).getPropertyValue("font-size"), zoom) + "px";
    }
    else if(elem.currentStyle) {
      elem.style.fontSize = getZoom(elem.currentStyle.fontSize, zoom) + "px";
    }
    else {
      elem.style.fontSize = getZoom(elem.style.fontSize, zoom) + "px";
    }
}

function getZoom(original, zoomer) {
  var fontSize = parseInt(original.split('px')[0]);
  if(fontSize == 1) {
    fontSize = 10;
  } else if (fontSize == 5) {
    fontSize = 24;
  } else if (fontSize == 3) {
    fontSize = 18;
  }
  fontSize += zoomer;
  return fontSize;
}

function go_home() {
  window.location.href = 'index.php';
}

function histories(direction) {
  if(direction == 1) {
    history.forward();
  } else if (direction == -1) {
    history.back();
  } else {
    window.location.reload();
  }
}