If you want to know how to properly repair the iphone 4S screen, there are a couple of things you need to know. The Apple iPhone 4S front glass, touch screen, and Retina LCD are fused together in the factory and assembled as one part.
To repair the iphone glass properly, it is not possible to replace only the glass using OEM replacement parts. The proper repair for a cracked iphone screen, touch screen problems, or damaged LCD is replacing the iphone 4S screen assembly.
The cost to repair your iPhone 4S screen is listed below and includes the OEM replacement part, labor, and a 90 day warranty.
Make sure you iPhone shows up when connected to iTunes or you may have other issues.
Since your checking your charging port, consider backing up your iPhone in iTunes before bringing it in. Better safe than sorry.