VBA code for Alert Message and highlight duplicate

[parscon]

I have about 852520 Recode in sheet1 in column a , I need a VBA code that check the column A and if find a duplicate items show me Alert Message and also highlight the duplicated item .

Please help me .

Thank you

[dazwm]

Can you not use conditional formatting?

[mancubus]

assume you have 10.000 dublicate values out of 852.250 rows of data. do you wish a message box appears 10.000 times on the screen and click ok each time?

why not use conditional formatting for duplicates from styles group in home tab since you seem to have office 2007+...