On the profile page I want to show three select boxes with Country/Region/City.
I have three boxes with the values in it with the code below, there is only one problem.
For example I have selected the country "The Netherlands" and I selected a region. If I switch the country to another country the region select box (and city select box) doesn't reset and fill with the regions/city's from the new selected country.

What am I doing wrong?

This is the added code for the three select boxes:
<div class="row">
<label for="Country"><span><?php _e('Country', 'gamma'); ?></span></label>
<div class="input-box"><?php UserForm::country_select(osc_get_countries(), osc_user()); ?></div>
</div>

<div class="row">
<label for="Region"><span><?php _e('Region', 'gamma'); ?></span></label>
<div class="input-box"><?php UserForm::region_select(osc_get_regions(), osc_user()); ?></div>
</div>

<div class="row">
<label for="City"><span><?php _e('City', 'gamma'); ?></span></label>
<div class="input-box"><?php UserForm::city_select(osc_get_cities(), osc_user()); ?></div>
</div>


@vansebas
You are missing javascript that will be doing auto-refresh of regions & cities, once you choose parent entry.

That's it, so simple that I forgot 
Added the javascript and everything is working fine