Call Webservice from JS, sending some data

hi,

I have a webservice created with asp, which is:

Imports System
Imports System.IO
Imports System.Text
Imports System.Web
Imports System.Web.Services
Imports System.Web.Services.Protocols<System.Web.Script.Services.ScriptService()><WebService(Namespace:="http://tempuri.org/")><WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)><Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
Public Class WBS_Actions
    Inherits System.Web.Services.WebService<WebMethod()>
    Public Sub TrackAction(byval sText as string)
        Dim path As String = "c:\MyTest.txt"
        Using fs As FileStream = File.Create(path)
            Dim info As Byte() = New UTF8Encoding(True).GetBytes(sText)
            ' Add some information to the file.
            fs.Write(info, 0, info.Length)
        End Using
    End Sub

End Class

On anoter website, I have a JS that calls this webservice like this:

function ActionDone() {
    var xhr = new XMLHttpRequest();
    xhr.open('POST', 'http://localhost:57358/WBS_Actions.asmx/TrackAction', true);
    xhr.setRequestHeader('Content-type', 'text/plain');
    xhr.send("test");
}

Now, the issue is that the file is not created with that code. Instead, if I changed the webservice to the code below, the file is created, but I am missing the option to send data from JS to the webservice.

Public Sub TrackAction()
        Dim path As String = "c:\MyTest.txt"
        Using fs As FileStream = File.Create(path)
            Dim info As Byte() = New UTF8Encoding(True).GetBytes("This is my text")
            ' Add some information to the file.
            fs.Write(info, 0, info.Length)
        End Using
End Sub

Any help would be much appreciated, thanks!

imendimu