diff --git a/DM_Weight/ViewModels/CheckRecordNewWindowViewModel.cs b/DM_Weight/ViewModels/CheckRecordNewWindowViewModel.cs
index 6c1772a..3be5dcb 100644
--- a/DM_Weight/ViewModels/CheckRecordNewWindowViewModel.cs
+++ b/DM_Weight/ViewModels/CheckRecordNewWindowViewModel.cs
@@ -145,7 +145,7 @@ namespace DM_Weight.ViewModels
         {
             int totalCount = 0;
             string strSql = @"SELECT optDate AS optdate,U.User_name AS operatorUser,R.User_name AS reviewerUser,Drug_spec AS drugSpec,Manufactory AS manufactory,Quantity FROM check_stock C 
-                                LEFT JOIN user_list U ON C.operator=U.ID  LEFT JOIN user_list R ON C.reviewer=R.ID WHERE C.machine_id='" + ConfigurationManager.AppSettings["machineId"] ??"DM1" +"'";
+                                LEFT JOIN user_list U ON C.operator=U.ID  LEFT JOIN user_list R ON C.reviewer=R.ID WHERE C.machine_id='" + (ConfigurationManager.AppSettings["machineId"] ??"DM1") +"'";
             if(StartDate!=null)
             {
                 strSql += " AND C.optDate>@OPTSTARTDATE ";