10 foot sliding french doors with screens

Hi my doors are about 2yrs old, but everytime I've opened my sliding screens they either go too far, and sometimes get caught, or when I close them, they stay open on one side because they are not perfectly centered which lets flies into my house. Did my builder fail to install a part that would fix this problem? Am I missing parts for my door/screens? Its a 10 foot french sliding door, natural wood interior, brown exterior. Please advise?