dhtmlxcombo combo-boxes with round corners

Suite and Optimus Suite 5
#1

Is it possible to change the shape of the combo-boxes in dhtmlxcombo, for example a combo-box with round corners (see attached example)?

#2

You may try to set border-radius in the following classes:
.dhx_combo_box{
.dhx_combo_list{
.dhx_combo_list div{
.dhx_selected_option{

in dhtmlxcombo.css