every half an hour once frequent urination

You do not specify if you are a man or a women.

Frequent urination in men is sometimes a sign of an enlarged prostate.

You have several tools available to you.  One would be to increase your awareness of what you are eating and drinking.  Typically acidic foods such as tomatoes, spicy foods, and diuretic beverages, including alcohol, soft drinks, tea, and coffee, can all increase bladder irritability.  You want to do your best to avoid these.  You can refer to http://my.clevelandclinic.org/disorders/overactive_bladder/hic_bladder_irritating_foods.aspx

for a complete list of these foods.  Another option available to you is to discuss with your doctor and he/she may prescribe different medications that can help your symptoms.  And finally a third option is behavioral training.  Keeping a log of your bathroom visits and knowing when it is just an urge vs. a need.  When it is not a need, because you just went to  the bathroom, you can work different relaxation techniques as well as pelvic floor strengthening exercises that will allow you to take control of your symptoms.