//var hide_empty_list=true; //uncomment this line to hide empty selection lists

var disable_empty_list=true; //uncomment this line to disable empty selection lists

addListGroup("Cities", "car-rentals");

addOption("car-rentals", "Select a City", "", "", 1); //Empty starter option
addList("car-rentals", "Islamabad", "Islamabad", "Islamabad");
addList("car-rentals", "Lahore", "Lahore", "Lahore");
addList("car-rentals", "Karachi", "Karachi", "Karachi");


addOption("Islamabad", "Select Location", "", "", 1); //Empty starter option
addList("Islamabad", "Islamabad International Airport", "Islamabad International Airport");
addList("Islamabad", "F-8 Markaz", "F-8 Markaz");


addOption("Lahore", "Select Location", "", "", 1); //Empty starter option
addList("Lahore", "Lahore International Airport", "Lahore International Airport");
addList("Lahore", "Regional Office", "Mall Road Office");


addOption("Karachi", "Select Location", "", "", 1); //Empty starter option
addList("Karachi", "Quaid-e-Azam International Airport", "Quaid-e-Azam International Airport");