empID increment on Add emp

Question

connect.Open();
        SqlCommand cmd = new SqlCommand("SELECT empID FROM emp WHERE empID=(SELECT max(empID) FROM emp);");
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        System.Data.SqlClient.SqlDataReader dr = null;
        dr = cmd.ExecuteReader();

        int age = Convert.ToInt32(textBox4.Text);

        int id = Convert.ToInt32(dr["empID"].ToString());
        textBox1.Text = (id + 1).ToString();


        string save = "INSERT INTO emp (empID, empLName, empFName, empAge, empGender, empAddress, empEmail, empUser, empPass, empType)  values('"
            + id + "','" + textBox2.Text + "','" + textBox3.Text + "','" + age + "','" + gender + "','" + textBox5.Text + "','"
            + textBox6.Text + "','" + textBox7.Text + "','" + textBox8.Text + "','" + postn + "')";

        SqlCommand cmdsave = new SqlCommand(save, connect);                
        cmdsave.ExecuteNonQuery();

        MessageBox.Show("Saved!");  
        connect.Close();

I can add employee when manually putting empID on my form, but I want it to be automatically added on my database by adding 1 on it.