Edit The Code:
See Result »
Try it Yourself - ©
w3ii.com
<!DOCTYPE html> <html> <body> <select id="car" onchange="ChangeCarList()"> <option value="">-- Car --</option> <option value="VO">Volvo</option> <option value="VW">Volkswagen</option> <option value="BMW">BMW</option> </select> <select id="carmodel"></select> <script> var carsAndModels = {}; carsAndModels['VO'] = ['V70', 'XC60', 'XC90']; carsAndModels['VW'] = ['Golf', 'Polo', 'Scirocco', 'Touareg']; carsAndModels['BMW'] = ['M6', 'X5', 'Z3']; function ChangeCarList() { var carList = document.getElementById("car"); var modelList = document.getElementById("carmodel"); var selCar = carList.options[carList.selectedIndex].value; while (modelList.options.length) { modelList.remove(0); } var cars = carsAndModels[selCar]; if (cars) { var i; for (i = 0; i < cars.length; i++) { var car = new Option(cars[i], i); modelList.options.add(car); } } } </script> </body> </html>