Retrieve the xml first, and reuse it every time you create a new dhtmlXCombo.
e.g using jQuery to retrieve the xml:
<div id="testA" style="width:200px; height:30px;"></div>
<div id="testB" style="width:200px; height:30px;"></div>
<div id="testC" style="width:200px; height:30px;"></div>
$(function () {
$.ajax({
type: "GET",
url: "getStatus.xml",
dataType: "xml"
}).done(function (response) {
var testA = new dhtmlXCombo("testA", "testA", 200),
testB = new dhtmlXCombo("testB", "testB", 200),
testC = new dhtmlXCombo("testC", "testC", 200);
testA.loadXMLString(response);
testB.loadXMLString(response);
testC.loadXMLString(response);
});
});
Alternatively if you are not using jQuery you can use dhtmlxAjax:
dhtmlxAjax.get("getStatus.xml", function (loader) {
var response = loader.xmlDoc.responseXML;
// ...
});