i am pretty sure that i am suffering from an allergy to dust. since we have hard wood floors, i can just imagine the dust flying aroung our apt. the only real symptom of it is that every morning i have sort of a crackly cough about an hour after i wake up and until i work up a little mucus (opaque whiteish yellow). after that i am ok for the most part. i have always had carpeting before which i imagine traps the dust better. the doctor didn´t really have much to say other than take an allergy pill. any other tips?

I would suggest, as I saw elsewhere, to get an air filtration system such as a HEPA Air Filter. Also, humidification can sometimes reduce floating dust and providing moisture to your mucous membranes increases their ability to ward off allergens and illnesses.

the symptom's of allergies are sneezing , runny nose, watery eyes .....the symptom's you describe sound like smoker's cough ...do you smoke or have you in the past ? if not , what type of heating and air conditioning is in your apartment ?

i do not smoke, never have.
and we have no air conditioning.
coughing is a symptom of allergies.

Coughing can be a symptome of allergies, but the coughing and mucus you describe don't seem like a dust allergy. However, if your doctor says to take an allergy pill, you ought to do that. You might want to try Benadryll. I've found that Drixoral Cold & Allergy works very well.
You may also want to consider going to see a doctor who specializes in allergies.