private void loginPictureBox_Click(object sender, EventArgs e) { var login = new MasterKey(this); login.ShowDialog(); if (isLoged) { loginPictureBox.Enabled = false; TabPage admin = new TabPage(); // administrator // admin.BackColor = System.Drawing.Color.White; admin.Location = new System.Drawing.Point(4, 38); admin.Name = "administrator"; admin.Size = new System.Drawing.Size(792, 527); admin.TabIndex = 7; admin.Text = "Administración"; // metroTabControl2.TabPages.Add(admin); } }