Server Error in '/' Application.

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 60:         bool flag = false;
Line 61:         row1 = dh.GetRow("select menu_son_mark,menu_show_front from sys_menu where menu_id='" + menu_id + "'");
Line 62:         if (row1["menu_son_mark"]!=null&&row1["menu_son_mark"].ToString() == "1")
Line 63:         {
Line 64:             dt = dh.GetRecord("select menu_son_mark,menu_show_front from sys_menu where parent_id='" + menu_id + "'");

Source File: c:\inetpub\wwwroot\App_Code\pageBase.cs    Line: 62

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
   pageBase.menu_son_mark(String menu_id) in c:\inetpub\wwwroot\App_Code\pageBase.cs:62
   pageBase.menu_id(String id) in c:\inetpub\wwwroot\App_Code\pageBase.cs:31
   Exhibition.Page_Load(Object sender, EventArgs e) in c:\inetpub\wwwroot\Exhibition.aspx.cs:34
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

Version Information: Microsoft .NET Framework Version:2.0.50727.8762; ASP.NET Version:2.0.50727.8762