
108 S.E.2d 594 (1959)
250 N.C. 355
BANK OF VARINA
v.
W. M. SLAUGHTER and wife, Nell V. Slaughter, James C. Slaughter and wife, Lucy L. Slaughter, and William B. Oliver, Trustee.
No. 469.
Supreme Court of North Carolina.
May 20, 1959.
*596 Thomas A. Banks, Raleigh, for plaintiff appellee.
Allen Langston, Raleigh, for defendant appellants.
RODMAN, Justice.
Defendants complain of rulings excluding a conversation between W. M. Slaughter and his wife, Nell V. Slaughter, made prior to the execution of the note and not communicated to plaintiff. No reason is advanced which would establish the competency of this testimony.
Defendants also assign as error the refusal of the court to permit W. M. Slaughter to testify with respect to negotiations with the bank president which culminated in the execution of the note and deed of trust.
"A contract is an agreement between two or more persons or parties on sufficient consideration to do or refrain from doing a particular act." Kirby v. Stokes County Board of Education, 230 N.C. 619, 55 S.E.2d 322, 327.
When the terms of a contract are established, the negotiations which produced the contract cannot enlarge or restrict its provisions and are therefore not competent as evidence in an action to enforce it. Bost v. Bost, 234 N.C. 554, 67 S.E.2d 745; Williams v. McLean, 220 N.C. 504, 17 S.E.2d 644; Home Owners' Loan Corp. v. Ford, 212 N.C. 324, 193 S.E. 279.
The note and deed of trust constituting the contract were in writing. They contained an express promise to pay such sums as the bank loaned not in excess of $25,000. This promise could not be contradicted or destroyed by parol testimony *597 that the makers would not be called upon to pay monies loaned pursuant to the contract. The very purpose of reducing it to writing was to avoid any controversy as to the terms of the contract. Neal v. Marrone, 239 N.C. 73, 79 S.E.2d 239; McLawhon v. Briley, 234 N.C. 394, 67 S.E.2d 285; Busbee v. Creech, 192 N.C. 499, 135 S.E. 326; De Loache v. De Loache, 189 N.C. 394, 127 S.E. 419; Rousseau v. Call, 169 N.C. 173, 85 S.E. 414.
The court, after reviewing the evidence and contentions of the parties, charged the jury that the burden of proof rested on plaintiff to establish by the greater weight of the evidence the sums loaned directly to defendants and the amount deposited to the credit of Farm Center at the direction of defendants, and if the plaintiff had failed to establish the full amount of its claim to answer the issue in the amount admitted by defendants to be owing. The charge was not prejudicial to defendants; it was more favorable than they were entitled to.
If the court's definition and explanation of "greater weight of the evidence" was not as full and complete as defendants thought necessary, they should have requested an instruction containing the desired definition and illustration. McAbee v. Love, 238 N.C. 560, 78 S.E.2d 405.
Likewise, if at the trial they thought, as they here contend, the court had not fully stated their contentions, they should have responded to the request made by the judge just before his final instruction. The court said: "Now, if there are any other instructions that counsel for either side request the Court to make I would like to have the request at thi time."
The record shows: "No response from counsel." It is now too late to complain. In re Will of Crawford, 246 N.C. 322, 98 S.E.2d 29; Strong, N.C. Index, Vol. 1, p. 101, n. 289.
No error.
