Please help to check when loading, error persists below code

Question

Please help to check when loading, error persists below code :-   1) Default.aspx "text/javascript"  src= "http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" >    "text/javascript" >   $(document).ready( function  () {   $.ajax({   type:  "POST" ,   contentType:  "application/json; charset=utf-8" ,   url:  "Default.aspx/BindDatatable" ,   data:  "{}" ,   dataType:  "json" ,   success:  function  (data) {   for  ( var  i = 0; i  $( "#gvDetails" ).append( " "  + data.d[i].UserId +  " "  + data.d[i].UserName +  " "  + data.d[i].Location +  " " );   }   },   error:  function  (result) {   alert( "Error" );   }   });   });      "text/css" >   table,th,td   {   border:1px solid black;   border-collapse:collapse;   }      "form1"  runat= "server" >   "gvDetails"  runat= "server" >   "#DC5807"  Font-Bold= "true"  ForeColor= "White"  />         2) Default.aspx code behind protected   void  Page_Load( object  sender, EventArgs e)   {   if  (!IsPostBack)   {   BindColumnToGridview();   }   }   private   void  BindColumnToGridview()   {   DataTable dt =  new  DataTable();   dt.Columns.Add( "UserId" );   dt.Columns.Add( "UserName" );   dt.Rows.Add();   gvDetails.DataSource = dt;   gvDetails.DataBind();   gvDetails.Rows[0].Visible =  false ;   }   [System.Web.Services.WebMethod]   public   static  UserDetails[] BindDatatable()   {   DataTable dt =  new  DataTable();   List  details =  new  List ();   using  (OracleConnection con =  new  OracleConnection( "Data Source=(DESCRIPTION ="    +  "(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xxx.xxx.xxx)(PORT=xxxx)))"    +  "(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=xxxxxx)));"    +  "User Id=xxxx;Password=xxxxxxxx;" ))   {   using  (OracleCommand cmd =  new  OracleCommand( "SELECT UserId,UserName FROM table" , con))   {   con.Open();   OracleDataAdapter da =  new  OracleDataAdapter(cmd);   da.Fill(dt);   foreach  (DataRow dtrow  in  dt.Rows)   {   UserDetails user =  new  UserDetails();   user.UserId = dtrow[ "UserId" ].ToString();   user.UserName = dtrow[ "UserName" ].ToString();   details.Add(user);   }   }   }   return  details.ToArray();   }   public   class  UserDetails   {   public   string  UserId {  get ;  set ; }   public   string  UserName {  get ;  set ; }   }

Laxmidhar Sahoo · Answer

perhaps this is run time error.   first take the code in try.... catch block then    give the break point when run at the top of the function and debug line   by line and tell in which line the controll go to catch block

Francky Frined · Answer

Below error message persists during compilation, please help

Laxmidhar Sahoo · Answer

insted of public   static  UserDetails[] BindDatatable()   use public   static  List  BindDatatable()   the return only details not details.toarray()