var myChunk=new Array(); // cache chunks here
  var chunkURL="site/tjChunk.php";
  
/*  pass id, destination element, callback function
    returns result array
*/
function getChunk(id, el, cbFN) {
	myChunk[id]=null; //-- no cache for testing !!!!!!!!!!!!!!
	
	if (myChunk[id]) {
$.log("---> cached tjChunk.js id=>"+id,{type:"err"}); /////////////////
		data = myChunk[id];
		data.el = el;

		if (cbFN) {
			cbFN (data);
		} else {
			$(e).html(data.chunk[0]);
		}

	} else {
$.log("=> tjChunk.js id=>"+id+" el=>"+el, {type:"war"}); /////////////////

		var jx=$.ajax({
			type: "POST",
			data: {
				id: id,
				el: el
			},
			dataType: "json",
			url: chunkURL
		})
    
		.error(function(data) {
			if (data.responseText) {
$.log("tjChunk.js 30 err resp data:", data.responseText);
			} else {
$.log("tjChunk.js 32 err noresp data:",data);
                e = data.el;
                if (cbFN) {
                    cbFN (data);
                } else {
                    $(e).html(data.chunk[0]);
                }
			}
		})
    
		.success(function(data) {
            $.log("tjChunk.js success 43 el:"+el+" data:",data, {type:"inf"});
			if(data.status=="OK") {
				myChunk[id]=data; //cache
				e = data.el;
				if (cbFN) {
					cbFN (data);
				} else {
					$(e).html(data.chunk[0]);
				}
			} else {
        
alert ("tjChunk.js #41 error! "+data.status);
			}
		});
	}
}