Update Window for Wix Installer

I makeing a Project and now my chef want for the realise of it an installer. I made one with WiX Tooltips. The problem is when I update the installer and run it, it gives me the same window as a fresh install. It shows the License and where i want to install it. Is there a way that it will tell me that I can install an update when a version already exists and not just a fresh install. Thanks for help