Chell testified that Charlotte said very little and Charles was the primary decision-maker. On March 6, 1974, a purchase in the joint names of Charlotte and Evelyn was made in the amount of $50,011.00. A second purchase in the amount of $50,000.00 was made on March 16,1974. On March 20, 1974, an account in the names of Charles and Evelyn was opened. On the authority of an executed blank stock assignment power, Charlotte’s mutual funds plus earnings were transferred to Charles and Evelyn, effective April 15, 1974. All records regarding this mutual fund were sent to Gardners. In order to make this investment, Charlotte borrowed $36,000.00 from her bank.
Charles again contacted Morrill to prepare the gift tax returns. He indicated to Morrill that the transfer occurred on December 23, 1974 instead of the actual date of transfer, April 15, 1974. The value of the mutual fund shares had declined by $2.77 per share, thus the gift value was under-reported by $28,769.22.
The $36,000.00 bank note was due in 1975. Gardners sold some of Charlotte’s blue chip stock, through the use of a stock power, and cashed a $6,000.00 certificate of deposit to pay the note.
In May of 1976, two more transactions occurred. First, a diamond gift, purchased for $5,500.00, was given to Evelyn. Second, 872 shares of Homestake Mining Company stock, valued at $32,700.00, were given to Charles. Charles testified at trial that both of these gifts were to help pay Evelyn’s hospital expenses. No gift tax returns were filed on either of these gifts.
Finally, in 1977, a camper top was purchased for Gardners for $310.96. Also, five checks signed by Charlotte, each in the amount of $333.36, were made payable to Arizona Title Insurance for the partial purchase of some land for Gardners.
Viewing this evidence in the light most favorable to the non-moving party, we find that substantial evidence was introduced at trial on the issues of Gardners’ active participation in the questioned transactions and that they unduly profited from the transactions which warranted the submission of this case to the jury. The trial court did not err in refusing to grant Gard-ners’ motion for directed verdict.2
Gardners contend that the trial court erred in instructing the jury. First, they claim two instructions should have been given which state that evidence of Charlotte’s obtaining independent legal advice, which was neither incompetent nor perfunctory, shows that her gifting was not the result of the exercise of undue influence.
The trial court has a duty to instruct the jury on the law applicable to a particular case. Jahnig v. Coisman, 283 N.W.2d 557 (S.D.1979); Egan v. Sheffer, 86 S.D. 684, 201 N.W.2d 174 (1972). Only those issues which are supported by competent evidence, however, should be presented to the jury. Ryken v. Blumer, 307 N.W.2d 865 (S.D.1981); Wolf v. Graber, 303 N.W.2d 364 (S.D.1981); Olesen v. Snyder, 277 N.W.2d 729 (S.D.1979).
Morrill’s first contact with Charlotte was on November 14, 1973. Prior to that time, Charlotte conducted all her legal affairs with attorney Robert Driscoll; however, he
2
In light of our holding that substantial evidence was introduced at trial regarding the presumption of undue influence arising out of a confidential relationship, we need not determine whether substantial evidence was introduced to prove the four elements of undue influence as set forth in Matter of Estate of Weickum, supra. Testimony regarding a lawsuit brought by Michael Black against Charles Gardner claiming misappropriation of partnership funds was also received into evidence at trial. Gardners claim this evidence is inadmissible under SDCL 19-12-5 to prove the third element of the undue influence test, namely, Charles’ propensity to exert undue influence over Charlotte. We decline to address this issue because we are not applying the four-part undue influence test and because Charles has failed to meet his burden of showing not only error, but also prejudicial error to the effect that under the evidence, the jury might and probably would have returned a different verdict if the evidence had been excluded. Watkins v. Ebach, 291 N.W.2d 765 (S.D.1980); Alberts v. Mutual Service Casualty Insurance Co., 80 S.D. 303, 123 N.W.2d 96 (1963). See also Lytle v. Morgan, 270 N.W.2d 359 (S.D.1978).