diff --git a/script/room.js b/script/room.js
index a7b3f90..d569154 100644
--- a/script/room.js
+++ b/script/room.js
@@ -901,19 +901,18 @@ var Room = {
 							.addClass('row_val')
 							.text(Engine.getIncomeMsg(income.stores[store], income.delay))
 							.appendTo(tt);
-						if (totalIncome[store] === undefined || totalIncome[store]['income'] === undefined) {
-							totalIncome[store] = {};
-							totalIncome[store]['income'] = 0;
+						if (!totalIncome[store] || totalIncome[store].income === undefined) {
+							totalIncome[store] = { income: 0 };
 						}
-						totalIncome[store]['income'] += Number(income.stores[store]);
-						totalIncome[store]['delay'] = income.delay;
+						totalIncome[store].income += Number(income.stores[store]);
+						totalIncome[store].delay = income.delay;
 					}
 				}
 			}
 			if(tt.children().length > 0) {
-				var total = totalIncome[storeName]['income'];
+				var total = totalIncome[storeName].income;
 				$('<div>').addClass('total row_key').text(_('total')).appendTo(tt);
-				$('<div>').addClass('total row_val').text(Engine.getIncomeMsg(total, totalIncome[storeName]['delay'])).appendTo(tt);
+				$('<div>').addClass('total row_val').text(Engine.getIncomeMsg(total, totalIncome[storeName].delay)).appendTo(tt);
 				tt.appendTo(el);
 			}
 		});