Facebook integration with PHP

[hemi519]

Hi All,

My issue is when a user come to our site if he already logged in facebook, the site should automatically take his facebook authentication details and should sign into my site. How is this possible through Facebook API or is there any other way. Can anyone tell how to this

[bluewalrus]

I haven't used this but it sounds like what you're looking for...

http://developers.facebook.com/docs/guides/web/#login