Error when call BSSV webservice

I have a problem when I call BSSV from javascript.
My call from javascript is:

var xmlhttp = new XMLHttpRequest();'POST', '', true);
//the following variable contains my xml soap request (that you can get thanks to SoapUI for example)
var sr =
'<?xml version = "1.0" encoding = "UTF-8"?><env:Envelope xmlns:env="" xmlns:ns1=""><env:Header/><env:Body><ns1:llamadaB55NCALL><arg0><szDataStructureString_DSS>10096</szDataStructureString_DSS><szReportID9_RTID>R55NETIQ</szReportID9_RTID><szReportVersion_RTVE>NET0001</szReportVersion_RTVE></arg0></ns1:llamadaB55NCALL></env:Body></env:Envelope>';

xmlhttp.onreadystatechange = () => {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) {

// Send the POST request
xmlhttp.setRequestHeader('Content-Type', 'text/xml; charset=UTF-8');
xmlhttp.setRequestHeader('SOAPAction', '');
xmlhttp.setRequestHeader('Host', '');
xmlhttp.setRequestHeader('Content-Length', '374');
xmlhttp.setRequestHeader('X-HTTPAnalyzer-Rules', '[email protected]:809');

The wsdl I posted from JDE is:

But the status of response is 500 always, and the message of this error is Couldn't create SOAP message due to exception: XML reader error: com.ctc.wstx.exc.WstxEOFException: Unexpected EOF in prolog
at [row,col {unknown-source}]: [1,0]