years ago i lived in a shared house and i had a ground floor bedroom, my bed was up against the window and i woke up in the middle of the night to find some bloke climbing through, i not sure who was more pertirfied, me at finding this bloke virtually in my bed or him stuck halfway through a window with a mad woman banging his head against the window screaming my head off, so i know how you feel, i invested in some window locks, so you can open the window so far then lock so it can't be opened any further.