How to Delete a Relationship in Microsoft Access

[uronmapu]

I have a file mdb: http://www.mediafire.com/?l3qf5klijkubkpe


Logon: admin/admin

In the table: T_HangHoa
I want to change Indexed (Yes (No Duplicates) to No) but can't
http://www.mediafire.com/view/?5duw2zq3a7pgdq6#

It have problem below:
http://www.mediafire.com/view/?on2nt1u4x6wb8am#

I selected Primary Key and remove but can't
http://www.mediafire.com/view/?44d9jbfp5rmin3h#
http://www.mediafire.com/view/?3w9dv2s9koh8adk#

Could you help to fix

Many thanks

[orange]

Go to the relationships window (in acc2003 it is Tools-->Relationships)
Select(click) the relationship you want, you'll get an option to delete/remove.

[uronmapu]

I'm using MS Access 2007
Could you help to fix my file in the link below?
http://www.mediafire.com/?l3qf5klijkubkpe
Many thanks

[uronmapu]

Description error detail
My file: http://www.mediafire.com/?g09b648dhv5q9ii
Run file , Select Hóa Đơn

Choose DaTH,

Type info, It will have problem below

Image has been scaled down 5% (800x197). Click this bar to view original image (836x205). Click image to open in new window.

I tryed to fix:

Select Table T_HangHoa

Changge Indexed from Yes to No but can't, error

Image has been scaled down 4% (800x230). Click this bar to view original image (831x238). Click image to open in new window.

I try to delete primary key, but can't


Please advices

[orange]

Try this
http://www.youtube.com/watch?v=zRkJD5CDvEU