text: document.getElementById("id_bussiness_version").innerHTML = "Logic version: 2018.11.26.16";
  var canvas = document.getElementById("id_canvas");
  canvas.addEventListener("touchstart", on_touch_start);
  canvas.addEventListener("touchmove", on_touch_move);
  canvas.addEventListener("touchend", on_touch_end);
  var canvas_bounding_rect = canvas.getBoundingClientRect();
  
  var last_pos_array = [];
  
  //-----------------------------
  function get_random_color()
  {
  	var litere = '0123456789ABCDEF';
  	var s = "#";
  	for (var i = 0; i < 6; i++)
  		s = s + litere[Math.floor(Math.random() * 16)];
  }
  //-----------------------------------
  function on_touch_start(e)
  {
  	for (var i = 0; i < e.changedTouches.length; i++){
  		var context = canvas.getContext("2d");
  		context.beginPath();
  		var last_pos = {x: e.changedTouches[i].pageX, 
  						y: e.changedTouches[i].pageY, 
  						id: e.changedTouches[i].identifier,
  						color: get_random_color()};
  		last_pos_array.push(last_pos);
  
  		context.fillStyle = last_pos_array[last_pos_array.length - 1].color;
  		context.strokeStyle = last_pos_array[last_pos_array.length - 1].color;
  		
  		context.arc(e.changedTouches[i].pageX - canvas_bounding_rect.left,
  					e.changedTouches[i].pageY - canvas_bounding_rect.top,
  					10,
  					0, 2 * Math.PI);
  		context.fill();
  		context.stroke();
  
  	}
  }
  //-----------------------------------
  function on_touch_move(e)
  {
  	e.preventDefault();
  	
  	for (var i = 0; i < e.changedTouches.length; i++){
  		var j = 0;
  		for (; j < last_pos_array.length; j++)
  			if (last_pos_array[j].id == e.changedTouches[i].identifier)
  				break;
  		
  		var context = canvas.getContext("2d");
  		context.beginPath();
  		context.lineWidth = 20;
  		context.fillStyle = last_pos_array[j].color;
  		context.strokeStyle = last_pos_array[j].color;
  		context.moveTo(last_pos_array[j].x - canvas_bounding_rect.left, last_pos_array[j].y - canvas_bounding_rect.top);
  		context.lineTo(e.changedTouches[i].pageX - canvas_bounding_rect.left,
  					e.changedTouches[i].pageY - canvas_bounding_rect.top);
  		context.stroke();
  		
  		context.beginPath();
  		context.lineWidth = 1;		
  		context.fillStyle = last_pos_array[j].color;
  		context.strokeStyle = last_pos_array[j].color;
  
  		context.arc(e.changedTouches[i].pageX - canvas_bounding_rect.left,
  					e.changedTouches[i].pageY - canvas_bounding_rect.top,
  					10,
  					0, 2 * Math.PI);
  		context.fill();
  		context.stroke();
  		
  		last_pos_array[j].x = e.changedTouches[i].pageX;
  		last_pos_array[j].y = e.changedTouches[i].pageY;		
  	}
  	
  }
  //--------------------------------------
  function on_touch_end(e)
  {
  	for (var i = 0; i < e.changedTouches.length; i++){
  		var j = 0;
  		for (; j < last_pos_array.length; j++)
  			if (last_pos_array[j].id == e.changedTouches[i].identifier)
  				break;
  			
  		last_pos_array.splice(j, 1);
  	}
  	
  }
  