<OperationContract()>
    <WebInvoke(Method:="GET", UriTemplate:="GetWorkbookHeaders/UserLogin={UserLogin}&SearchText={SearchText}", ResponseFormat:=WebMessageFormat.Json, RequestFormat:=WebMessageFormat.Json, BodyStyle:=WebMessageBodyStyle.Bare)>
    Function GetWorkbookHeaders(ByVal UserLogin As String, ByVal SearchText As String) As String

Dim reader As SqlDataReader = command.ExecuteReader
                While reader.Read
                    ReturntedData = reader.GetString(0)
                End While

<webHttp defaultOutgoingResponseFormat="Json" automaticFormatSelectionEnabled="false" helpEnabled="true"   />