Conversion failed when converting the varchar value to data type int [closed]

If you are getting  error than you have to so simply this

 public void dropExhibition(DropDownList Drop, string exid)

    {

        string value = "";

        SqlCommand cmd2 = new SqlCommand("Select * from Exhibition_Master where Exhibition_Status='Open'", con);

        SqlDataAdapter sda = new SqlDataAdapter(cmd2);

        DataTable dt = new DataTable();

        sda.Fill(dt);

        foreach (DataRow dr in dt.Rows)

        {

            string s=dr["Team_Code"].ToString();

            string ex = dr["Exid"].ToString();

            string [] a = s.Split(',');

            foreach (var num in a)

            {

                if (num == exid)

                {

                    value +=ex +",";

                }

            }

        }

        cmd = new SqlCommand("select Distinct Exhibition_Name,Exid from dbo.Exhibition_Master where Exid IN(" + value.Trim(',') + ") and Exhibition_Status=@Exhibition_Status", con);

        cmd.Parameters.AddWithValue("@Exhibition_Status", "Open");

        try

        {

            con.Open();

            Drop.AppendDataBoundItems = true;

            Drop.DataSource = cmd.ExecuteReader();

            Drop.DataTextField = "Exhibition_Name";

            Drop.DataValueField = "Exid";

            Drop.DataBind();

        }

        catch (SqlException)

        {

        }

        finally

        {

            con.Close();

        }

}