Very urgent! plz have a look at this

Question

hi
can anybody help me to develop a jsp page in which
i want to include 3 dynamic dependant lists .
Ex:-->Country-->state-->district-->city
all the values r stored in MySql tables.
independently i am able to display all the values for the first time(default)
but when i change the opiton for country,then the state field values r to be changed and the district ,city fields should be set empty.when i select a STATE-->then district should get the values related to that state. and so on.
But i didn't get how to do this.
plz help me?
awaiting a quick response form you
thank you

Answer 1

AJAX code: to populate each combo use seperate ajax call. then populate the combobox.
function getHTTPObject() {     
     var xmlhttp;
     if (window.XMLHttpRequest) // if Mozilla, Safari etc
          xmlhttp = new XMLHttpRequest();
     else if (window.ActiveXObject){ // if IE
          try {
               xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
          catch ( e ){
               try{
                    xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
               catch ( e ){}
     return xmlhttp;
function myAJAX(string1) {
    var URL =  "requiredAction.do";
    var queryString = "name="+escape(string1);
    httpObject.open( "Post", URL, true );
    httpObject.onreadystatechange = callBackFn;
    httpObject.setRequestHeader( "Content-Type", "application/x-www-form-urlencoded" );
    httpObject.send(queryString);
function callBackFn() {
    if (httpObject.readyState == 4)
         if (httpObject.status == 200)
          var result = httpObject.responseText;
          //code here to manipulate result
     var valarray=attrVal.split(","); //get the result in a comma delimited string from action class (also from BO resultset)
     for (var i=0; i < valarray.length;++i){
          addOption(document.getElementById("combobox"), valarray, valarray[i]);
function addOption(selectbox,text,value)
     var optn = document.createElement("OPTION");
     optn.text = trim(text);
     optn.value = trim(value);
     selectbox.options.add(optn);