Calling custom webservice using java script

 //Calling custom web service using java script

var xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
                var soapXml = "<?xml version='1.0' encoding='utf-8'?>";
                soapXml += "<soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema' xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'>";
                soapXml += "<soap:Body>";
                soapXml += "<GetObjectTypeCode xmlns='http://tempuri.org/'>";
                soapXml += " <Entity>" + entityname + "</Entity>";
                soapXml += " </GetObjectTypeCode>";
                soapXml += " </soap:Body>";
                soapXml += "</soap:Envelope>";


                xmlhttp.open("POST", "/customwebserviceurl.asmx", false);
                xmlhttp.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
                xmlhttp.setRequestHeader("Content-Length", soapXml.length);
                xmlhttp.setRequestHeader("SOAPAction", "http://tempuri.org/GetObjectTypeCode");
                xmlhttp.send(soapXml);


                var resultValue = xmlhttp.responseXML.childNodes[1].nodeTypedValue;