HI ! I would like to compare values from a textbox with data from a table. I tried this code but i got the error that the input string was in the wrong format! code:

string connectionString = 
    "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=save.mdb";

try
{

   database = new OleDbConnection(connectionString);
   database.Open();
   string queryString = "SELECT zivila.naziv,users.user_name FROM (obroki_save "
       + " LEFT JOIN zivila ON zivila.ID=obroki_save.ID_zivila) "
       + " LEFT JOIN users ON users.ID=obroki_save.ID_uporabnika "
       + " WHERE users.ID='" +Convert.ToInt16(id.iDTextBox.Text)+"'"; 
   loadDataGrid(queryString);
}
catch (Exception ex)
{
   MessageBox.Show(ex.Message);
   return;
}