function type(){
  var j = 0;
  var strOut="";
  for(j;j<speed;j++){
	  if (i < txt.length)
	  {
  		strOut+=txt.charAt(i);
  		document.getElementById("demo").scrollTop = document.getElementById("demo").scrollHeight;
  		i++;
	  } else break;
  }
  document.getElementById("demo").innerHTML += strOut;

  if (i < txt.length) {
	  setTimeout(type,1);
  }
}