protected override void InternalValidate() { base.InternalValidate(); if (_PassRank == null) { AddError(PASS_RANK_PROPERTY, PASS_RANK_PROPERTY_ERROR); } else if (_PassRank <= 0) { AddError(PASS_RANK_PROPERTY_ERROR2); } else if (HasPageItem) { int?passRank; int p = PageItem.GetTotalPoints(out passRank); if (passRank != null && p < passRank) { AddError(PASS_RANK_IS_MORE_THAN_SUM_OF_RANKS); } } int buttonsCount = 0; foreach (Control c in Control.Controls) { if (c.Tag is HtmlButton) { buttonsCount++; } } if (buttonsCount != 1) { if (buttonsCount == 0) { AddError(NO_BUTTONS_ERROR); } else { AddError(MORE_THEN_ONE_BUTTON); } } }