Sum field in Subform footer

[vfisher]

I am using Access 97. I have a sum field in the footer of a subform that sums the values of each record in the subform. However, it doesn't add the value of a record until the focus goes to a new row. Since I'm validating that value against a field on the parent form, I need to set the focus to the first first in the new row when I start my validation. Can anyone tell me how to do this?

Thanks.