LINQ Stored Procedure

Have the followin开发者_Python百科g Stored procedure for a search form. I use Linq and have problem to get the result of this procedure....am I in the wrong way in procedure or in linq?

You can see my linq down here too..I have tried different ways..but now i need your help :)

ALTER PROCEDURE [dbo].[SearchPostit]
 (
 @message varchar(1000)='', 
 @writer varchar(50)='',
 @mailto varchar(100)='',
 @date varchar(50)=''
 )
AS
 SELECT P.Message AS Postit, P.Mailto AS 'Mailad till', P.[Date] AS Datum, U.UserName AS Användare  
 FROM PostIt P 

 LEFT OUTER JOIN [User] U ON P.UserId=U.UserId

    WHERE P.message LIKE '%'+@message+'%' AND  U.UserName LIKE '%'+@writer+'%' AND P.Mailto LIKE '%'+@mailto+'%' 
    AND P.Date LIKE '%'+@date+'%' 
    GROUP BY P.Message, U.UserName, P.Mailto, P.[Date]



System.ComponentModel.DataObjectMethodAttribute(System.ComponentModel.DataObjectMethodType.Select, true)]
        public DataSet SearchPostit(string message, string writer, string mailto, string date)
        {
            var dc = new LinqClassesDataContext();

            List<SearchPostitResult> p = dc.SearchPostit(message, writer, mailto, date).ToList();

            DataTable dt = new DataTable();

            dt.Columns.Add("Message", typeof(string));
            dt.Columns.Add("UserName",typeof (string));
            dt.Columns.Add("E-mail", typeof(string));
            dt.Columns.Add("Date",typeof(DateTime));

            foreach(SearchPostitResult res in dc.SearchPostit(message, writer, mailto, date))
            {
                DataRow row = dt.NewRow();

                row["Message"] = res.Postit;
                row["UserName"] = res.User;
                row["E-mail"] = res.Mailto;
                row["Date"]=res.Date;

                dt.Rows.Add(row);
            }
                DataSet ds = new DataSet();
                ds.Tables.Add(dt);
                return ds;
            }

        }

Without knowing much about the error, the only thing I can guess (and this is a total guess) is that it looks like the PostIt.Date field in the database isn't a DateTime, and you're trying to put it into a DateTime field in a DataTable. I'm not sure that works.

As a side point, why would you need the overhead of creating a datatable anyway? What's wrong with the collection Linq to Sql is giving back to you?