hi ganesh - midges like still air, dull light, forestry, water and dark clothing.
They are more active in the early morning and the early evening, don't bother you indoors and are put off by a good repellent like DEET or Shoo (easily avilable when you get to the destination) - and also Nivea for some reason......and tend to go away once you start walking, but stop for 1 second and they will be on you.
Basic advice is cover up, use repellent on face and hands and as another tip, make sure the pooch has a good flea and tick repellent on before getting outdoors, otherwise there will be a lot of other little visitors bothering everyone for a long time after the holiday.........
http://www.midgeforecast.co.uk/home/forecast.a sp has an online guide as to expected problems and tons of info here:
http://www.albawest.com/midges.html if you're bored.
I'd suggest the best break you could have if you can only go in July is go high, rather than coast, hope for cool weather with a breeze and make sure you are near lots of pubs......The midge can be a real pest, but don't let the potential put you off. You may well find there isn't a big problem in the location you decide on, but at least you can be aware of the possibility.
Hope you have a pure dead brilliant time!!