Wrong

One of the screws in the back door fell out.  It holds part of the locking mechanism in place.  Looked for it everywhere but couldn't find it.  Perhaps the dog scoffed it.  So I bought some more.  Only needed one but of course they only come in bags of 50.  
I bought the wrong size.  I measured it very carefully but don't really have the right tool to do it accurately.  So I bought 3mm (diameter).  Turned out we need 4mm.  Sigh.  Kinda sums up my day.