single button to call multiple forrms

Simplest copy paste way (say only 3 different forms exists and will be forever ;-)  )

private void button1_Click(object sender, EventArgs e)

{

                if (MdiChildren.ToList().Exists(anyAcc =>

                {

                                return anyAcc.Name == "Acc1";

                }) == false)

                {

                                Form acc = new Form();

                                acc.Name = "Acc1"; // this is the key!

                                acc.Text = acc.Name;                                                          

                                acc.MdiParent = this;

                                acc.Show();

                                return;

                }

                if (MdiChildren.ToList().Exists(anyAcc =>

                {

                                return anyAcc.Name == "Acc2";

                }) == false)

                {

                                Form acc = new Form();

                                acc.Name = "Acc2"; // this is the key!

                                acc.Text = acc.Name;

                                acc.MdiParent = this;

                                acc.Show();

                                return;

                }

                if (MdiChildren.ToList().Exists(anyAcc =>

                {

                                return anyAcc.Name == "Acc3";

                }) == false)

                {

                                Form acc = new Form();

                                acc.Name = "Acc3"; // this is the key!

                                acc.Text = acc.Name;

                                acc.MdiParent = this;

                                acc.Show();

                                return;

      }

I have used MDI interface.

By my opinion, for using on the pannel the UserControls is better.

;-)