"Data type mismatch in criteria expression"

Question

Hey guys ! I have a problem when i want to insert values from textboxes to my access database ! When i want to save i get that error ("Data type mismatch in criteria expression") The code:

    string conString = "Provider=Microsoft.Jet.OLEDB.4.0;"
        + "Data Source=C:\\Users\\Simon\\Desktop\\test5\\test5\\test5\\save.mdb";

    OleDbConnection empConnection = new OleDbConnection(conString);


    string insertStatement = "INSERT INTO aktivnosti_save "
                         + "([ID_uporabnika],[ID_aktivnosti],[kalorij]) "
                         + "VALUES (@ID_uporabnika,@ID_aktivnosti,@kalorij)";

    OleDbCommand insertCommand = new OleDbCommand(insertStatement, empConnection);

    insertCommand.Parameters.Add("@ID_uporabnika", OleDbType.Char).Value = textBox3.Text;
    insertCommand.Parameters.Add("@ID_zivila", OleDbType.Char).Value = iDTextBox.Text;
    insertCommand.Parameters.Add("@kalorij", OleDbType.Char).Value = textBox2.Text;
    empConnection.Open();

    try
    {
        int count = insertCommand.ExecuteNonQuery();
    }
    catch (OleDbException ex)
    {
        MessageBox.Show(ex.Message);
    }
    finally
    {
        empConnection.Close();
        textBox1.Clear();
        textBox2.Clear();   
    }
}