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 86:             t8_2 = dbto.Rows[8]["SM"].ToString();
Line 87: 
Line 88:             le = Request.QueryString["le"].ToString();
Line 89:             DataSet dslb = part.SelectAllZTAll("NewsClass_Table", " where le='" + Request.QueryString["le"].ToString() + "' order by Path desc", "");
Line 90:             DataTable dblb=dslb.Tables[0];

Source File: d:\web\\News.aspx.cs    Line: 88

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
   News.Page_Load(Object sender, EventArgs e) in d:\web\\News.aspx.cs:88
   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) +91
   System.Web.UI.Control.LoadRecursive() +74
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1