Merging two objects in javascript

mergeObjects.js

var aggregateData = function(wb, rb){


	for(var k in  rb)	{	//
	
		if(Object.prototype.toString.call(rb[k]) == '[object Object]'){
			if(wb.hasOwnProperty(k)){
				
				var ob1 = wb[k];
				var ob2 = rb[k];
				/*console.log("IF", ob1, ob2);*/
				if(Object.keys(ob1).length > 0 || ob1!=null){
					aggregateData(ob1, ob2, -1, function(err, result){
						if(err){
							console.log(err);
						}
						else{
							//console.log("merge result:", result);
						}
					});
				}
				else{
					//console.log(Object.keys(ob1).length, Object.keys(ob2).length);
				}	
			}
			else{
				console.log("ELSE");
				wb[k] = rb[k];
			}		
		}
		else if(Object.prototype.toString.call(rb[k]) == '[object Array]'){
			if(wb[k]){
				wb[k] = wb[k].concat(rb[k]);
			}
			else{
				wb[k] = rb[k];
			}
		}
		else{
			if(wb[k]){
				wb[k] = wb[k] + rb[k];
			}
			else{
				wb[k] = rb[k];	
			}	
		}
	}

	if(i>0){
		if(r.length > i+1){
			console.log("****moving to next obj****");
			aggregateData(wb, r, i+1, function(err, result){
			 	if(err){
			 		callback(err, null);
			 	}
			 	else{
			 		callback(null, result);
			 	}
			});
		}
		else{
			//console.log("weekly obj:", wb);
			callback(null, wb);
		}
	}
	else{
		callback(null, wb);
	}
}