private void mnuAddCate_Click(object sender, EventArgs e)
{
if (addCate != null)
{
addCate.Show();
}
else
{
addCate = new AddCategory();
addCate.MdiParent = clsFormProvider.mainF;
addCate.Show();
addCate.FormClosing += addCate_FormClosing;
}
}
public void addCate_FormClosing(object sender, FormClosingEventArgs e)
{
addCate = null;
}