Problem in replacing old image for a user in codeigniter

Hii i have successfully uploaded main image and thumbnail image in some folder and storing filename to the databas开发者_Python百科e, but now i want to replace the old file with new file by replacing the file in the folder.

can anyone suggest me what i should do for upadting image????

---

Do the same thing as for new image file.

But this is not too good idea. Browser caches static files like images. If you don't change file name browser will show old image.