Neb. Rev. Stat. § 27-103

(1) Error may not be predicated upon a ruling which admits or excludes evidence unless a substantial right of the party is affected, and: (a) In case the ruling is one admitting evidence, a timely objection or motion to strike appears of record, stating the specific ground of objection, if a specific ground was not apparent from the context; or (b) In case the ruling is one excluding evidence, the substance of the evidence was made known to the judge by offer or was apparent from the context within which questions were asked. (2) The judge may add any other or further statement which shows the character of the evidence, the form in which it was offered, the objection made, and the ruling thereon. He may direct the making of an offer in question and answer form. (3) In jury cases, proceedings shall be conducted, to the extent practicable, so as to prevent inadmissible evidence from being suggested to the jury by any means, such as making statements or offers of proof or asking questions in the hearing of the jury. (4) Nothing in this rule precludes taking notice of plain errors affecting substantial rights although they were not brought to the attention of the judge.