Set indicator date to training date if it is left blank in bulk edit form

[anyalynn]

Unfortunately, this cannot be done with a table trigger because this table is updated by other datapages as well.  I have a report that searches training dates, lists providers, and sets an indicator based on the fact that the provider took a training.  The indicator can be set to yes for each provider with a bulk edit.  An indicator date needs to be added when the indicator is set to yes.  If this date is not added, I want it to default to the training date.  It seems like it would be easy but I can't get the indicator date to save the training date value in the bulk edit if it is blank.  There should be a way to take the training date from the results page, set the indicator date equal to that, and then if the user doesn't change that when setting the indicator in the bulk edit to yes/checked, it would save that training date in that indicator date field.  

I looked into doing this with a trigger, loading the training date into the indicator date field on load, using a placeholder, and JavaScript, but I can't get the value to save.  If anyone has advice on how to do this, I would appreciate knowing about it. 

Thanks.