Code not updating the right record, allowing multiple records with same unique ID, HELP!!

I desperately need your help.

This is an excel wks designed for data entry in sheet "Input", data storage in sheet "PartsData".

"Order ID" is supposed not to allow duplicates. When a new record is inserted with an existing Order_ID, user is asked if he wants to update existing record.

BUG? -- As you can see in "PartsData", im starting off with 4 records (order_ID s 10100, 10101, 10102 and 10103). If i try to insert a new record in "Input" wks with Order_ID 10100 but with different values for "Part", "Location" and "Quantity", Excel tells me that that's an existing order_ID and asks if i want to UPDATE the existing record. I say YES.

RESULT -- Excel does NOT UPDATE the original Order_ID=1100 record, instead it creates ANOTHER Order_ID=1100 record OVERWRITING the previously existing Order_ID=10102 record. I lose one record and get a new record

Can someone tell me what's wrong? I need this corrected, as i was adapting this code for a work project, and know nothing about VBA... Thank you so much! - Joćo V.

Can someone please help?

As you can see, when Excel UPDATES a record (Order_ID already existed), it SIMPLY OVERWRITES THE THIRD RECORD, everytime. Adding a new record (Order_ID not previously existed) seems to work fine...

How do i fix the VBA code?.... Im completely helpless.

Thank you. Im still having trouble translating the excel formulas to portuguese. Im getting an error message.

But tell me this: i don't want to be able to insert a record with an Order_ID i already have in my history (PartsData)... when i try to insert an already existing Order_ID, i want the macro to ask me if i want to UPDATE the existing record, and if i say YES, i want the old record to be replaced (ie: all fields with different values from the existing ones must change to the new values). In other words: whatever happens, i never want more than 1 instance of the same Order_ID in my data collection.

From what i understand, im guessing youre making a combination of two fields (Order_ID + Part) to be the database key, and i need the database key to be ORDER_ID... Can you help? J

I just wrote back to the original code author, and sent her this link (2 Excel files and my note requesting help): https://www.sugarsync.com/pf/D8722812_66980811_647566
Does any of you guys have 5 minutes to look at this problem?

MickG im still counting on you :-)

Joćo V.