I am working an iphone app where i am giving the option of downloading an image to user's iphone. Following is my code for downloading of image.

UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:urlAddress]]];
NSString *pngFilePath = [[[NSString stringWithFormat:@"%@/",docDir] stringByAppendingString:[NSString stringWithFormat:@"%@",couponID]] stringByAppendingString:@".png"];
NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];
[data1 writeToFile:pngFilePath atomically:YES];

My above code works fine but now i want to give option of deleting the image downloaded from above code. Can some one please advice me how can i delete a image file from iphone.