Collection was modified; enumeration operation may not execute.

void counts()
    {
        foreach(RepeaterItem items in repeat.Items)
        {
            HiddenField comment_like = (HiddenField)items.FindControl("comment_like");
            Label user_counts = (Label)items.FindControl("user_counts");
         
            if (Request.QueryString["id"] != null)
            {
                int id;
                id = Convert.ToInt32(Request.QueryString["id"].ToString());
                con = new SqlConnection(str);
                con.Open();
                cmd = new SqlCommand("sp_command_count", con);
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddWithValue("@eid", id);
                cmd.Parameters.AddWithValue("@comment_id", comment_like.Value);
                da = new SqlDataAdapter(cmd);
                dt = new DataTable();
                da.Fill(dt);
                con.Close();

                if (dt.Rows.Count > 0)
                {
                    DataRow dr = dt.Rows[0];
                    user_counts.Text = dr["total_count"].ToString() + "of" + dr["like_count"].ToString();

                    repeat.DataSource = dt;
                    repeat.DataBind();
                    review_panel.Visible = true;
                }
                else
                {
                    review_panel.Visible = false;
                }
            }
        }
    }