private void btnAdd_Click(object sender, EventArgs e)
{
frmUser userinfo = new frmUser();
userinfo.TopLevel = false;
this.Parent.Controls.Add(userinfo);
userinfo.Dock = DockStyle.Fill;
userinfo.Show();
}
private void btnEdit_Click(object sender, EventArgs e)
{
User user = convertSelectedRowDataToUser();
frmUser userinfo = new frmUser(user);
userinfo.TopLevel = false;
this.Parent.Controls.Add(userinfo);
userinfo.Dock = DockStyle.Fill;
this.Visible = false;
userinfo.Show();
}