Cómo hacer enlaces de formulario en php

Operación del nodo Dom

var data_sheng = new Array('Hunan','Hubei','Guangdong','Guangxi'); p>

var data_shi = new Array();

data_shi[0] = new Array('Changsha','Zhuzhou','Xiangtan','Yiyang','Loudi', 'Yueyang ','Huaihua');

data_shi[1] = new Array('Wuhan','Wuchang','Hankou','Pingjiang');

data_shi[ 2] = new Array('Guangzhou','Dongguan','Shenzhen','Heyuan','Meizhou','Zhanjiang');

data_shi[3] = new Array('Nanning', 'Guilin ');

window.onload = function(){

var sheng = document.getElementById('sheng');

var k = 0 ;

for(var i in data_sheng){

var op = nueva opción(data_sheng[i],data_sheng[i]);

k++;

sheng.options[k] = op

}

función change_shi(obj){

var sheng = obj.

var k = getKey(sheng);

var shi = document.options[i] = op;

}

función getKey(str){

for(var i in data_sheng){

if(data_ sheng[i] == str) {

devolver i;

}

devolver 0;

}

<./html>