(a) The right of a party to perfect an appeal from a judgment, order or decree of the trial court to the Supreme Court shall not be conditioned upon his having filed in the trial court a motion for a new trial, but in the event a motion for a new trial is filed in the trial court by a party adversely affected by the judgment, order or decree, no appeal to the Supreme Court may be taken until subsequent to the ruling by the trial court on the motion for a new trial. This provision shall not apply, however, to an appeal from an order of the Corporation Commission.

(b) If a motion for a new trial be filed and a new trial be denied, the movant may not, on the appeal, raise allegations of error that were available to him at the time of the filing of his motion for a new trial but were not therein asserted.