private void 도서관리ToolStripMenuItem_Click(object sender, EventArgs e)
{
frmBook frm = new frmBook();
frm.MdiParent = this;
frm.Show();
}
private void 도서관리ToolStripMenuItem_Click(object sender, EventArgs e)
{
frmBook b1 = new frmBook();
b1.MdiParent = this;
b1.Show();
b1.Activate();
}