var s=["s1","s2"]; 
var opt0 = ["所在地","地区"]; 


function setup() 
{ 
 for(i=0;i<s.length-1;i++) 
  document.getElementById(s[i]).onchange=new Function("change("+(i+1)+")"); 
 change(0); 
} 
function Dsy() 
{ 
 this.Items = {}; 
} 
Dsy.prototype.add = function(id,iArray) 
{ 
 this.Items[id] = iArray; 
} 
Dsy.prototype.Exists = function(id) 
{ 
 if(typeof(this.Items[id]) == "undefined") return false; 
 return true; 
} 

function change(v){ 

 //var str="0";  之前是这个 我只想要省市 就改成下一个
 var str="0_0"; 
 for(i=0;i<v;i++){ str+=("_"+(document.getElementById(s[i]).selectedIndex-1));}; 
 var ss=document.getElementById(s[v]); 
 with(ss){ 
  length = 0; 
  options[0]=new Option(opt0[v],0); 
  //options[0]=new Option(opt0[v],opt0[v]); 
  if(v && document.getElementById(s[v-1]).selectedIndex>0 || !v) 
  { 
   if(dsy.Exists(str)){ 
    ar = dsy.Items[str]; 
   
    for(i=0;i<ar.length;i++)
     {
       av=ar[i].split("|");

    options[length]=new Option(av[0],av[1]); 
     }
    if(v)options[1].selected = true; 
   } 
  } 
  if(++v<s.length){change(v);} 
 } 
}