FBConnect - uploading images to Wall

Question

Hi All,

i've configured FBConnect and it uploads to the wall, but what i want to do is take a screenshot and then upload the screenshot to FB.

In the below code there is an image but as a url. Can i intersect this and put in my screenshot image?

 FBStreamDialog *dialog = [[[FBStreamDialog alloc] init]autorelease];
             dialog.userMessagePrompt = @"Tell your friends about Fridgit!!:";
             dialog.attachment = [NSString stringWithFormat:@"{\"name\":\"Facebook Connect for iPhone\",\"href\":\"http://developers.facebook.com/connect.phptab=iphone\",\"caption\":\"Caption\",\"description\":\"Description\",\"media\":[{\"type\":\"image\",\"src\":\"screenShot\",\"href\":\"http://developers.facebook.com/connect.php?tab=iphone/\"}],\"properties\":{\"another link\":{\"text\":\"Facebook home page\",\"href\":\"http://www.facebook.com\"}}}", self.screenShot];                
 [dialog show];

}

i know all the code is default i haven't edited it yet incase i can't do what i want to do.

Cheers