Is there a shorter way to write the following if statements?
Add all items to a list and do a foreach instead.

var buttons = new List&lt;Button&gt;
{
    tx_cmb_Circuits1,
    tx_cmb_Circuits2,
    ...
};

foreach ( var button in buttons )
{
    if ( !String.IsNullOrEmpty( button.Text.Trim() ) )
    {
        emp.CircuitEmail_Group_Rels.Add(
            new Circuit_Email_Group_Rel
            {
                Circuits = (Circuits) button.SelectedItem,
                Group = emp
            } );
    }
}


P.S.: Consider giving your variables better names. No real need for abbreviations like tx_cmb nowadays.