Text box calculation based on another text box

[Krays23]

Hi

I have this text box

txtExpectedDeliveryHUBactual

I would like when this text box has anything in it (will always be a date)

TxtBoxshipactual

to look at this date in TxtBoxshipactual and then take the amount of shipping days needed from TblDelivery_method and add it too that date each record in the form has a Airbus MSN number I need to make sure it adds the amount of shipping days associated with that MSN number from the table in photo which I assume it should as its looking at that record set or do I need to add that field in my main data tbl?

also id like when that delievery date box has data in it to put the days delta to customers needs in the text box at bottom

TxtDaysdeltatoplan


Thanks again for all your help im learning all the time thanks

Dan