private void listBoxGrps_DoubleClick(object sender, EventArgs e)
{
string grpname = (sender as ListBox).SelectedItem.ToString();
GroupForm groupForm = new GroupForm(serviceMess, labelLogin.Text, grpname);
groupForm.Show();
}
private void buttonNewGroup_Click(object sender, EventArgs e)
{
GroupForm groupForm = new GroupForm(serviceMess, labelLogin.Text, null);
groupForm.Show();
}