dhtmlxGrid and Datastore parse

Suite and Optimus Suite 5
#1

hi.
dhtmlx is very new for me and may be I don’t see something obvious, but I can’t understand why my datastore parse doesn’t work as i expect. Here is full sample:

<html>
<head>
	<link rel="STYLESHEET" type="text/css" href="dhtmlx.css">
	<script src="dhtmlx.js"></script>
</head> 
 
<body>
<script>

	dhtmlx.image_path='imgs/';

	var main_layout = new dhtmlXLayoutObject(document.body, '1C');

	var cell_1 = main_layout.cells('a');
	cell_1.hideHeader();
	
	var mydata = new dhtmlXDataStore();
	mydata.parse([{"id":"1", "value_date":"11/01/1982", "description":"some birthday", "comments":"good boy"},{"id":"2", "value_date":"11/01/1982", "description":"dummy date 01", "comments":""}], "json");

	var grid_1 = cell_1.attachGrid();
	grid_1.setIconsPath('imgs/');
	
	grid_1.setHeader(["Base Date","Description","Comments"]);
	grid_1.setColTypes("ed,ed,ed");
	grid_1.setColumnIds('value_date,description,comments');
	grid_1.init();
	
	var mydata2 = new dhtmlXDataStore({
		url:"grid_test_orig.json",
		datatype:"json"
	});
	
	grid_1.sync(mydata);
	//grid_1.sync(mydata2); // grid_test_orig.json is the same as in mydata.parse
</script>
</body>
<html>

I’m trying to use Grid this Datastore which use json object. If I’m using local json file (comment grid_1.sync(mydata) and uncomment grid_1.sync(mydata2)) grid is shown normally, but if i’m using datastore parse with SAME json - nothing is shown inside grid (and no errors in console)
Thanks for any advice.