how to call my webservice

I have created the following webservice:
    <WebMethod()> _
    Public Function SaveProspect(ByVal APIKey As String, ByVal campaignID As String, ByVal Prosp As Prospect) As Integer
            Return prospectDAL.SaveProspectDetails(campaignID, Prosp.Email, Prosp.Firstletters, Prosp.Firstname, Prosp.Middlename, Prosp.Lastname _
            , Prosp.Birthdate, HttpContext.Current.Request.UserHostAddress.ToString)
    End Function
   
Now, I want to call it. But I have no idea how :)

Ofcourse I want people from all kinds of clients (linux/windows/...) and languages (JAVA/.NET/PHP) to call this service.

Could anyone help me? :)
 
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