Consumption webservice with error: unsupported content type

My first question is: Can I call the WebService directly via JQUERY / AJAX or do I need to have something in PHP or some other backend language to perform the integration?

If it is possible only with JQUERY / AJAX , it follows the problem.

I have the following WebService :

http://IP:PORTA/wsexecbo/WebServiceExecBO?wsdl

In this WebService I have the following function:

http://IP:PORTA/wsexecbo/WebServiceExecBO?wsdl/userLogin

I send a user (no password) and it returns me a token.

Follow my custom.js :

$(document).ready(function() {
var soapMessage = 
  "<?xml version='1.0' encoding='UTF-8' standalone='no'?>" +
  "<soapenv:Envelope xmlns:soapenv='http://schemas.xmlsoap.org/soap/envelope/' xmlns:ser='http://service.execbo.ws.framework.totvs.com'>" +
      "<soapenv:Header/>" +
      "<soapenv:Body>" +
      "<ser:userLogin>" +
      "<arg0>user</arg0>" +
      "</ser:userLogin>" +
      "</soapenv:Body>" +
  "</soapenv:Envelope>";

  var wsUrl = "http://IP:PORTA/wsexecbo/WebServiceExecBO?wsdl/userLogin";
  $.ajax({
      type: "POST",
      dataType: "xml",
      url: wsUrl,
      data: soapMessage,
      success: function(data) {
          console.log(data);
      },
      error: function(error) {
          console.log(error);
      }
  });
}); 

But it always returns this:

<env:Envelope xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'>
    <env:Header>
    </env:Header>
        <env:Body>
            <env:Fault xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'>
            <faultcode>env:Server</faultcode>
            <faultstring>
                Unsupported content type: application/x-www-form-urlencoded; charset=UTF-8
            </faultstring>
            </env:Fault>
        </env:Body>
</env:Envelope>

I made some tests by putting these options:

contentType: "text/xml"
contentType: "application/xml"

But nothing solves it. Would anyone know what's going on and how can I resolve this?