function ajax_request(script_url,value,target_div){    var url = script_url + value;    var httpRequest;    document.getElementById(target_div).innerHTML = '<select id="cities" style="width:100%;"><option value="">Retrieving cities...</option></select>';    if (window.XMLHttpRequest) { /* Mozilla, Safari, ... */        httpRequest = new XMLHttpRequest();        if (httpRequest.overrideMimeType) {            httpRequest.overrideMimeType('text/xml');            /* See note below about this line */        }    }     else if (window.ActiveXObject) { /* IE */        try {            httpRequest = new ActiveXObject("Msxml2.XMLHTTP");        }         catch (e) {            try {                httpRequest = new ActiveXObject("Microsoft.XMLHTTP");            }             catch (e) {}        }    }    if (!httpRequest) {        alert('No se puede crear un instancia XMLHTTP');        return false;    }       httpRequest.onreadystatechange = function() { alertContents(httpRequest, target_div); };    httpRequest.open('GET', url, true);    httpRequest.send('');}function alertContents(httpRequest, target_div){    if (httpRequest.readyState == 4)    {        if (httpRequest.status == 200)        {                        ajax_response = httpRequest.responseText;                        document.getElementById(target_div).innerHTML = ajax_response;        }        else        {            alert(httpRequest.status);            alert('Problema width the request');        }    }}