Im new, how to open up 1 form in either Invoice or Quotes

private void addNewClientToolStripMenuItem_Click(object sender, EventArgs e)

        {

            frmClient g_Client = new frmClient ("Add");

            g_Client .WindowState = FormWindowState.Normal;

            g_Client.Show();

        }

this is the button to edit client.

private void EditClientToolStripMenuItem_Click(object sender, EventArgs e)

        {

            frmClient g_Client = new frmClient ("Edit");

            g_Client .WindowState = FormWindowState.Normal;

            g_Client.Show();

        }

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Now we are at the Client form.

int m_intCourseID;

public frmClient(string AddEdit)

        {

            InitializeComponent();

            m_strAddEdit = AddEdit;

        }

private void frmClient_Load(object sender, EventArgs e)

            if (m_strAddEdit == "Edit")

            {

                btnSave.Text = "Update";

                this.Text = "Update Client";

            }

            else if (m_strAddEdit == "Add")

            {

                this.Text == "Add New Client";

            }