如何使用 GET 或 POST 檢索 CITY 值，就像可以使用 $_POST['stt'] 使用 STATE 值一樣？ps：堆棧溢出的新手，所以請建議更好的提問方式:)var state_arr = new Array("Andaman & Nicobar");var s_a = new Array();s_a[0] = "";s_a[1] = " Alipur | Andaman Island | Anderson Island | Arainj-Laka-Punga | Austinabad | Bamboo Flat | Barren Island ";function print_state(state_id) {  // given the id of the <select> tag as function argument, it inserts <option> tags  var option_str = document.getElementById(state_id);  option_str.length = 0;  option_str.options[0] = new Option('Select State', '');  option_str.selectedIndex = 0;  for (var i = 0; i < state_arr.length; i++) {    option_str.options[option_str.length] = new Option(state_arr[i], state_arr[i]);  }}function print_city(city_id, city_index) {  var option_str = document.getElementById(city_id);  option_str.length = 0; // Fixed by Julian Woods  option_str.options[0] = new Option('Select City', '');  option_str.selectedIndex = 0;  var city_arr = s_a[city_index].split("|");  for (var i = 0; i < city_arr.length; i++) {    option_str.options[option_str.length] = new Option(city_arr[i], city_arr[i]);  }}print_state("sts");<form>  <select onchange="print_city('state', this.selectedIndex);" id="sts" name="stt" class="form-control" required></select>  <select id="state" class="form-control" required></select></form>