How To Delete Multi Rows From Sql With Parameter?

 USE [MyWebsite]
GO
/****** Object:  StoredProcedure [dbo].[DeletUserFromAdmin]    Script Date: 3/21/2013 7:54:08 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER proc [dbo].[DeletUserFromAdmin]

@userid int

as

DELETE FROM [dbo].[Users]
      WHERE usr_Id in (@userid) 

 protected void Button1_Click(object sender, EventArgs e)
    {

        string id = "0";
        foreach (GridDataItem mm in grdAllUsers.Items)
        {

            if (mm.Selected)
            {
                id +="," + mm.GetDataKeyValue("usr_Id");
                Literal1.Text = id;
            }
            

        }

        Admin delet = new Admin();
        string req = delet.DeleteUserFromAdmin(id);
        id = string.Empty;
        LoadGridAllUsers();
        Literal1.Text += "REquest:" + req;

    }

SqlCommand cmd = new SqlCommand("DeletUserFromAdmin", con);
        cmd.CommandType = CommandType.StoredProcedure;

        cmd.Parameters.Add("@userid", SqlDbType.Int).Value = id;

        try
        {
            if (con.State == ConnectionState.Closed)
            {
                con.Open();
            }

            if (cmd.ExecuteNonQuery() > 0)
            {
                return "Succ";
            }
            else
            {
               return "UnSucc";
            }
        }

        catch(Exception ex)
        {

            return ex.Message;
        }
        finally
        {

            con.Close();
        }
    }