/**
 * checkVotes
 *  form: the form to validate
 *
 *  Validate user-entered vote selection via the given form.
 *  Submits the form if all three choices have been selected, and the user has agreed to the Terms of Voting
 */
function checkVotes(form) {
    var firstPlace, secondPlace, thirdPlace;

    // get selected first, second and third place choices from the form
    firstPlace = getSelectedRadioButtonValue( form.firstPlace );
    secondPlace = getSelectedRadioButtonValue( form.secondPlace );
    thirdPlace = getSelectedRadioButtonValue( form.thirdPlace );

    // verify that a selection was made for each of the first, second and third places
    if( firstPlace == null )
        errorBox.appendContent( "err_firstPlace", "You must select your choice for First Place." );
    else
        errorBox.eraseError( "err_firstPlace" );

    if( secondPlace == null )
        errorBox.appendContent( "err_secondPlace", "You must select your choice for Second Place." );
    else
        errorBox.eraseError( "err_secondPlace" );

    if( thirdPlace == null )
        errorBox.appendContent( "err_thirdPlace", "You must select your choice for Third Place." );
    else
        errorBox.eraseError( "err_thirdPlace" );

    // verify that the user has agreed to the Terms of Voting
    if( ! form.votingTermsAgreement.checked )
        errorBox.appendContent( "agreement", "You must agree to the Terms of Voting." );
    else
        errorBox.eraseError( "agreement" );

    if( errorBox.isEmpty() )
        form.submit();
    else {
        errorBox.setVisible( true );
        scroll(0,0);
    }

}

function getSelectedRadioButtonValue(radioButtonSet) {
    for(i=0; i<radioButtonSet.length; i++)
        if( radioButtonSet[i].checked )
            return radioButtonSet[i].value;
    return null;
}