function getCurrentFontFactor()
{
  var current_factor = $.ajax({
         url: "/ajax_dojob.php",
         data: "get_fontsize_factor",
         async: false
       }).responseText;

  return parseFloat(current_factor);
}
function getCurrentFontSize()
{
  var current_fontsize = $("body").css("font-size");
  return parseFloat(current_fontsize.split("px")[0]);
}

function increaseFontSize(maximum_factor)
{ 
  if(getCurrentFontFactor() < maximum_factor)
  {
       var new_factor = parseFloat(getCurrentFontFactor()) + 0.1;
       current_fontsize = getCurrentFontSize();
       var new_fontsize = Math.round((current_fontsize * new_factor /getCurrentFontFactor())/0.1)*0.1;
       
       $.get("/ajax_dojob.php", { fontsize_factor: new_factor} );
       $("body").css("font-size", new_fontsize)
  }
}

function decreaseFontSize(minimum_factor)
{ 
  if(getCurrentFontFactor() > minimum_factor)
  {
       var new_factor = parseFloat(getCurrentFontFactor()) - 0.1;
       current_fontsize = getCurrentFontSize();
       var new_fontsize = Math.round((current_fontsize * new_factor /getCurrentFontFactor())/0.1)*0.1;
       
       $.get("/ajax_dojob.php", { fontsize_factor: new_factor} );
       $("body").css("font-size", new_fontsize)
  }
}

function standardFontSize(standardSize)
{
  var current_factor = getCurrentFontFactor();
  var current_fontsize = getCurrentFontSize();
  var std_fontsize = Math.round(current_fontsize / current_factor);
  
  $.get("/ajax_dojob.php", { fontsize_factor: 1} );
  $("body").css("font-size", std_fontsize);
}