function get_http_data(url,call_back,xml_obj){xml_obj.onreadystatechange=call_back;xml_obj.open("GET",url,true);xml_obj.setRequestHeader("If-Modified-Since","Sat, 1 Jan 2005 00:00:00 GMT");xml_obj.send(null);}function GetXmlHttpObject(){var xmlHttp=null;try
{xmlHttp=new XMLHttpRequest();}catch(e){var _ieModelos=new Array('MSXML2.XMLHTTP.5.0','MSXML2.XMLHTTP.4.0','MSXML2.XMLHTTP.3.0','MSXML2.XMLHTTP','Microsoft.XMLHTTP');var success=false;for(var i=0;i<_ieModelos.length&&!success;i++){try{xmlHttp=new ActiveXObject(_ieModelos[i]);success=true;}catch(e){}}}return xmlHttp;}