text: $(window).scroll(function(){
      if ($(window).scrollTop() >= 60) {
         $('nav').addClass('fixed-header');
      }
      else {
         $('nav').removeClass('fixed-header');
      }
  });
  
  function myFunction() {
      window.print();
  }
  
  var qrcode = new QRCode(document.getElementById("qrcode"), {
  	width : 100,
  	height : 100
  });
  
  function makeCode () {		
  	var elText = document.getElementById("text");
  	
  	if (!elText.value) {
  		alert("Input a text");
  		elText.focus();
  		return;
  	}
  	
  	qrcode.makeCode(elText.value);
  }
  
  makeCode();
  
  $("#text").
  	on("blur", function () {
  		makeCode();
  	}).
  	on("keydown", function (e) {
  		if (e.keyCode == 13) {
  			makeCode();
  		}
  	});