In the Matter of the Civil Commitment of Kimberly Sadek.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1994).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C1-96-1110

In Re the Marriage of:

Katherine L. Bicek, n/k/a Katherine Fritsche, petitioner,

Respondent,

vs.

Kenneth R. Bicek,

Appellant.

 Filed November 26, 1996

 Affirmed

 Parker, Judge

Scott County District Court

File No. 904777

Lorraine S. Clugg, Kissoon, Clugg, Linder & Dittberner, Ltd., 3205 West 76th Street, Edina, MN 55435-5244 (for respondent)

Ronald L. Moersch, Hvistendahl & Moersch, P.A., 311 South Water Street, Northfield, MN 55057 (for appellant)

Considered and decided by Parker, Presiding Judge, Willis, Judge, and Foley, Judge.[*]

 U N P U B L I S H E D O P I N I O N

 PARKER, Judge

Appellant Kenneth Bicek contests the denial of his motion to vacate a default order and judgment which required him to pay respondent Katherine Bicek (n/k/a Katherine Fritsche) child support for the parties' daughter retroactive to April 12, 1994, support arrearages of $5,500, and outstanding health care expenses for the children of $318. The order and judgment also transferred his interest in unclaimed personal property to respondent and required him to pay attorney fees. Because we conclude that the district court did not abuse discretion in denying appellant's motion to vacate and in granting attorney fees, we affirm and we award respondent $750 in attorney fees upon this appeal.

 D E C I S I O N

Appellant moved to vacate the default order and resulting judgment under Minn. R. Civ. P. 60.02(1), which provides relief for "mistake, inadvertence, * * * or excusable neglect." The appropriate method to seek review of a default order on a marriage dissolution issue (granted under chapter 518) is to move the district court for relief under Minn. Stat. § 518.145 (1994), which also allows relief for mistake, inadvertence, or excusable neglect. See Lindsey v. Lindsey, 388 N.W.2d 713, 716 n.1 (Minn. 1986) (district court lacks jurisdiction to vacate chapter 518 judgment under Minn. R. Civ. P. 60.02). Because the district court did not mention whether it recognized the motion under the rule or the statute, we assume the district court properly reviewed and addressed the motion under Minn. Stat. § 518.145, subd. 2. See Loth v. Loth, 227 Minn. 387, 392, 35 N.W.2d 542, 546 (1949) (appellate court cannot presume a district court erred).

1. Motion to Vacate the Default Judgment

While Minnesota recognizes a liberal policy in favor of reopening default judgments, the right to relief from a default judgment is not absolute. Riemer v. Zahn, 420 N.W.2d 659, 661 (Minn. App. 1988) (citing Hinz v. Northland Milk & Ice Cream Co., 237 Minn. 28, 30, 53 N.W.2d 454, 455-56 (1952)). Whether to vacate a default order and judgment rests largely within the district court's discretion and will not be reversed absent a clear abuse of discretion. Id. A party seeking to set aside a default judgment on the basis of excusable neglect must show (1) a reasonable defense on the merits; (2) a reasonable excuse for the failure or neglect to act; (3) action with due diligence after notice of entry of judgment; and (4) no substantial prejudice will result to the opponent. Id.

A. Reasonable Defense on the Merits

The 1991 judgment dissolving the parties' marriage granted respondent custody of the parties' two minor children and $300 per month child support "until one minor child attains the age of * * * 18." The judgment contained no provision for continuing child support for the younger child. Respondent moved the court to correct the apparent "clerical error" in the judgment. See Minn. R. Civ. P. 60.01 (allowing corrections for clerical error); Johnson v. Johnson, 379 N.W.2d 215, 218 (Minn. App. 1985) ("clerical error" is any error made by the court or the parties in drafting and includes an error arising from oversight or omission). While appellant originally argued to the district court that there was no error in the dissolution judgment, he conceded on appeal that he must pay child support for his second child and contested merely the amount set by the court, claiming that his income has decreased.

Any decrease in appellant's income is irrelevant to respondent's motion to correct the clerical error. In 1991, the dissolution court and the parties set appellant's monthly child support for both children at $300 under the statutory guidelines, based on appellant's stipulated monthly income of $1,000. Upon respondent's motion to correct the clerical error, the district court corrected the judgment's language to incorporate the amount of child support owed for one child, as set by the guidelines, and based on appellant's stipulated monthly income. Under proper circumstances, a future court may retroactively modify the support for 1994 and 1995 based on a change in appellant's income, but a motion for modification would be required for a court to address that issue. See Minn. Stat. § 518.64 (1994 & Supp. 1995) (addressing modification of child support).

Respondent contends the district court properly recognized that the parties and the dissolution court did not intend to relieve appellant of his support obligation for the younger child during her minority. The dissolution court's failure to mention support for that child after the elder child's eighteenth birthday is illogical; the court provided no rationale for abruptly terminating support, and the omission appears to be a scrivener's error. Because appellant made no real showing on the merits of this issue and because he now agrees he must pay support for his younger child, we conclude that the district court did not abuse discretion in determining that appellant offered no reasonable defense to the motion for correction.

Respondent also moved the district court to enforce and implement provisions of the dissolution judgment regarding health care expenses and certain personal property. See Minn. Stat. § 518.171, subd. 10 (1994) (providing authority to enforce medical support orders as child support); Hanson v. Hanson, 379 N.W.2d 230, 233 (Minn. App. 1985) (authorizing district court to implement and clarify dissolution decrees). Appellant waived any claim on these issues when he failed to address them in his brief to this court. See Melina v. Chaplin, 327 N.W.2d 19, 20 (Minn. 1982) (failure to address an issue in an appellate brief results in waiver). Because appellant failed to offer a reasonable defense to any of the items at issue, and because we cannot conclude that it was an abuse of the district court's discretion to reject appellant's explanation for his failure to appear at the default hearing, the district court did not err by denying appellant's motion to vacate.

B. Reasonable Excuse

Appellant claimed he did not appear at the default hearing because he did not receive notice of it. The district court made a credibility determination that he did not believe appellant. It is not our function to reverse a credibility determination unless there has been a clear abuse of discretion. See Minn. R. Civ. P. 52.01.

Respondent showed that notice of the motion was properly mailed to appellant and his dissolution attorney on February 2, 1996. See Kelley v. Moe, 387 N.W.2d 664, 668 (Minn. App. 1986) (stating that in the context of service by mail, "once a letter is properly mailed, the risk of nondelivery is on the addressee"). Respondent also stated she had attempted to contact appellant several times in May and June of 1994, but he refused her communication. Moreover, appellant admitted receiving a copy of the February 29, 1996, order, which was mailed to the same address as that to which the notice of the hearing was sent. On this record, we cannot conclude that the district court abused discretion in concluding that appellant's excuse was not credible.

C. Due Diligence and Substantial Prejudice

The record indicates that appellant acted with due diligence because he moved to vacate within three weeks of receiving notice of the judgment, and there is no showing that respondent would suffer prejudice were the judgment to be reopened. See Reimer, 420 N.W.2d at 662 (finding due diligence when defendant filed motion to vacate and scheduled hearing within eight weeks of learning of the default judgment, and stating that delay and added expense alone do not equate substantial prejudice because defendant could be required to pay costs and disbursements). A showing of these two factors, without more, does not meet appellant's burden. See Wiethoff v. Williams, 413 N.W.2d 533, 536 (Minn. App. 1987) ("Although one weak factor may be overcome by three strong factors, there is no authority by which we can conclude that two weak factors are overcome by two strong factors").

2. Attorney Fees

Appellant contests the district court's orders awarding respondent attorney fees. Because appellant's brief fails specifically to address attorney fees, however, we deem this issue waived. See Melina, 327 N.W.2d at 20.

Respondent also moved this court to award $1,449 in attorney fees for the costs incurred in responding to this appeal. Attorney fees on appeal may be granted where an appeal unreasonably contributes to the length or expense of the proceeding or upon a showing of need where the payor has the ability to pay the fees and the recipient has proceeded in good faith. Minn. Stat. § 518.14, subd. 1 (1994). While this appeal had comparatively little merit, we award fees on the basis of need. Respondent's attorney provided an affidavit supporting the fees incurred in her legitimate, good-faith response to this appeal. Respondent's affidavit in support of her motion for the correction and her affidavit in response to appellant's motion to vacate demonstrate her need for an attorney fee award. Because the affidavits in the record indicate that respondent and the children have been living on a modest income, without child support for almost two years, and appellant has maintained a more affluent lifestyle, we award attorney fees of $750. See Johnson v. Fritz, 406 N.W.2d 614, 616 (Minn. App. 1987) (allowing evidence of lifestyle to impute income higher than reported).

  Affirmed.

[ ]* Retired judge of the Minnesota Court of Appeals, serving by appointment pursuant to Minn. Const. art. VI, § 10.