Blocking Duplicate entries in excel table with data validation

[JeremyHill]

Hi All,

I am very new to this forum but using excel for a while. I've reading through some of the threads referring to my title but not exactly what I am looking for.
I even tried the online tutorials with no success. I think I'm doing something wrong.

http://s52.photobucket.com/user/PokemonGT/media/exceldata valid.png.html

The table I created has headers and the criteria header is "Job No."
As previously mentioned I have tried the data validation procedure with no success.

Please help.

Thanks

 

[blbat]

I don't click on links, so I have not seen what you posted at photobucket. I'm sure some of the local Excel Gurus will be around shortly...but this is what I use to prevent Dupes in my Spreadsheets:

    If Target.Cells.Count > 1 Or IsEmpty(Target(1, 1)) Then Exit Sub 
     
    If Not  Intersect(Target, Range("A2:A1000")) Is Nothing Then 
        If WorksheetFunction. CountIf(Range("A2:A1000"), Target) > 1 Then 
             MsgBox Target & " Already exists" 
            Application.EnableEvents = False 
            Application.Undo 
            Application.EnableEvents = True 
        End If 
    End If

 

[JeremyHill]

Thanks for the coding. am I correct to paste this into the sheet?

 

[JeremyHill]

I don't click on links, so I have not seen what you posted at photobucket. I'm sure some of the local Excel Gurus will be around shortly...but this is what I use to prevent Dupes in my Spreadsheets:

    If Target.Cells.Count > 1 Or IsEmpty(Target(1, 1)) Then Exit Sub 
     
    If Not  Intersect(Target, Range("A2:A1000")) Is Nothing Then 
        If WorksheetFunction. CountIf(Range("A2:A1000"), Target) > 1 Then 
             MsgBox Target & " Already exists" 
            Application.EnableEvents = False 
            Application.Undo 
            Application.EnableEvents = True 
        End If 
    End If

Hi blbat,

i pasted the code in the worksheet and changed the coding to look at the range of cells but no positive result. i'm trying to upload a screenshot of my sheet but having difficulty doing so.
Thanks.