Download popup for image

Hello friends, First I have to thank you all, whenever I posted my problem here surely someone helping me.

I have one more question about file downloads.

I have certain file types includes jpg, gif, png images. When user clicked on the links for these file types they should not try to display in the browser. Instead it should be asked to download.

How can I achieve this?

ok friends. Now I have the solution. No need to reply. thanks…