Hayi --
One way:
Lets say that you enter the IDs in column A and you have a label in A1.
A2 will be the next empty cell.
Activate A2, the empty cell.
Activate Data|Validation.
Choose Custom for Allow.
Enter as Formula:
=COUNTIF($A$1:A1,A2)
If so desired, you might want to add a message such as "ID exists -- Enter another." on the Error Alert tab.
Click OK.
Copy down A2 as far as you need.
Caveat. This method offers no protection against Copy and Paste.
Aladin
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Hi
You will also need to add =1 to the end of the countif
=COUNTIF($A$1:A2,A2)=1
HTH
Jacob
--
Jacob: You're right, the formula is incomplete. Thanks pointing out that. However, I had a slightly different formula in mind:
=COUNTIF($A$1:A1,A2)=0
Aladin
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That right I didnt test mine it the countif = 1 then the first value will fail, duh.
Jacob : You're right, the formula is incomplete. Thanks pointing out that. However, I had a slightly different formula in mind: =0 ==
Hi,
Thanks dears for ur comments.
but i m still having prob.
Can u tell me what shoul i write in A2 (suppose it is the desired column where i d't want duplication). What should i write in the formula text box of formula (Data---Validation---Customise----Formula)
Just tell write what should i write there.
Thanks
bye
Thanks Dear
You have solved my problem.
Thanks again
Hayi