try this code
menuStrip1 control add to splitContainer1.Panel2
MenuStrip menuStrip1 = new MenuStrip();
menuStrip1.Location = new System.Drawing.Point(40, 200);
ToolStripMenuItem menu1 = new ToolStripMenuItem("File");
ToolStripMenuItem menuItem1 = new ToolStripMenuItem("Send SMS", null);
menuStrip1.Items.Add(menu1);
menu1.DropDownItems.Add(menuItem1);
this.splitContainer1.Panel2.Controls.Add(menuStrip1);