Why form does not die evn object has been destroyed

Question

Dear
I am opening a form a menu click
private void newToolStripMenuItem_Click(object sender, EventArgs e)
{
Form frm = new Form();
frm.StartPosition = FormStartPosition.CenterScreen;
frm.MdiParent = this;
frm.Show();
}
The form is opening fine But I have a question.
When i passes through these statesments after frm.show() the object "frm" must be die,But form does not clse it self, how it is done,
I mean i want to know,if i am out the brases means object does not exists but it's form exists how it is happning,
Please correct me .