Yeah all my forms work and if you select Book_ID the combo box opens and as im using multiple columns it displays the books title and uses that as an alias but the ID is inserted into the database (this was suggested in an earlier post), that works fine.
But I want the book_price box to find the price of the book that is selected in Book_ID combo box.
the record source of the form is Orders tablebut the Book_ID and Book_Price boxes are in the subform which has the record source Order_Details
I couldnt find record source of the Book_ID combo box but it has the control source of Book_ID and the row source of:
SELECT Books.Book_ID, Books.Title FROM Books ORDER BY Books.Title;
And for the Book_Price combo box the row source is:
SELECT retail_Price FROM Books WHERE Book_ID=Forms![Order_Details Subform]!Book_ID;
This is a code I interpretted from another website but it doesn't work at all.