Name to resize iphone 6 image

This way I was always able to use the same image name in a line of code like backgroundimage.png when using a background image in the toolbar, and when deployed on iphone 5 it automatically uses backgroundimage @ 2x.png. Now that the iphone 6 needs a resized @ 2x.png image, how can I distinguish this in my code? what I mean is that now I cannot use the same image name for my modified image 6 in my code as my original image.png because both 5 and 6 will have the same name.

I have to write an if statement checking if the app is running on 6 and then deploy my code with the specific image name iphone 6 @ 2x.png?