u have, if you don't know exactly, don't worry, because Sony Ericsson Themes Creator also includes a photo gallery of the supported models.
After that, the program will show you all the customizable features and images. Maybe the most difficult part is to choose the picture you want to include, the rest is as easy as 123.
Finally if you create a theme and you want to distribute it, fill in the Author field to sign it.
Don't hesitate, download it and personalize your mobile.