how to prevent opening a form multiple times in c#
<p>i have created an application in which a menustrip is present in which 2 buttons are there, one for ADD, and another for UPDATE &amp; both controls are in a single form, means a button of add &amp; update is there in a single form, whenever i press add button in menustrip update button will be disabled, and when i press update on menustrip the add button will disable. how to do this? i m doing this by show method but that form is opening multiple times using show().</p>

<pre><code>    private void addRecordsToolStripMenuItem_Click(object sender, EventArgs e)
    {
           Form1 f2 = new Form1();
           f2.MdiParent = this;
           f2.Show();
           f2.button1.Enabled = true;

    }

    private void updateRecordsToolStripMenuItem_Click(object sender, EventArgs e)
    {
                Form1 f2 = new Form1();
                f2.MdiParent = this;
                f2.Show();
                f2.button2.Enabled = true;
                f2.button1.Enabled = false;

    }
</code></pre>
