AlphaFrog

First of all, thanks for the help. Now the major problem is solve it is down to details.
If you are still available to help, it would be great.

PART 1)
Referring back to the attached file before,
(Column F) Existing Company is A, B, C. and for each exiting company there is at least 1 detail (Column J).
However, if there is a company D but it doesn't have any detail (Column J) yet, the data validation result will be result from last entry.

Example
situation: Given then Company D is added but has no detail referred to it yet.

Column A Column B
Company B details for company B
Second Entry after... choosing "company B"
Company D details for company B

Sadly, this produce a incorrect findings. Is there a way to add something like

if range("A2")'s result = "" then range("B2").validation.delete
OR
if range("B2")'s result = "" then _
range("B2").validation.delete
msgbox "none matching results found", vbOKonly

PART 2)
Is there any way to have the data validation index to start at 0 on thisworkbook_open?

Thank you very much