How to Chnge Position forms in window application C#.dot net

sir one question sir how to minimize and maxi,ize form in according to main form when i minimize the main page all the form minimize and when i maximize all the form maximize i write code like this :-
private void frm_Main_Resize(object sender, EventArgs e)
{

if (this.WindowState == FormWindowState.Minimized)
{
foreach (Form frm in Application.OpenForms)
{
frm.WindowState = FormWindowState.Minimized;
}
}
else if (this.WindowState == FormWindowState.Normal)
{
foreach (Form frm in Application.OpenForms)
{
frm.WindowState = FormWindowState.Normal;
}
}
}