IE7之前版本创建XHR对象

<pre name="code" class="javascript">

    function createXHR(){        if(typeof arguments.callee.activeXString != "String"){            var versions = ["MSXML2.XMLHttp.6.0", "MSXML2.XMLHttp.3.0", "MSXML2.XMLHttp"], i;            for(int i = 0; i<versions.length; i++){               try{                    new ActiveXObject(versions[i]);                    arguments.callee.activeXString = versions[i];                    break;               }catch(ex){                    //continue               }            }        }             return new ActiveXObject(arguments.callee.activeXString);    }