private void listarClientesToolStripMenuItem_Click(object sender, EventArgs e)
{
if (listClient == null)
{
listClient = new frmListarClientes();
listClient.MdiParent = this;
listClient.FormClosed += new FormClosedEventHandler(listClient_FormClosed);
listClient.Show();
}
}
void listClient_FormClosed(object sender, EventArgs e)
{
listClient = null;
}
