Date Data Validate in form and subform

[ImranJKhan]

Have a form called tbl_Registration with a subform called tbl_HomeVisit . The form lists fields from a table Registration that has a one to many relation with table HomeVisit which has its field listed in the subform . For every Registration there are several homevisits. the table homevisit and subform tbl_homevisit have a Date field named VisitDate. I am trying to validate the date either at the table level or form level. The date field which needs to be updatable, must have atleast a 3 month gap from the previous homevisit. I have tried the following>= Max([visitdate]) + 90but it gives an error as followsThere is a 'the funtion yuo entered can't be used in this expression' in the form control's VlidationRule property. etc.please helpimran

 

[mderby]

you should the built in date function to perform arithmetric process.

try this A= Date - means today date. then use this
B=
DateDif(«interval», «date1», «date2», «firstweekday», «firstweek»)

If B >= 30 then update date.
You could use the help to file up the parameter of the function.

hope it help.