Unauthourized error

I'm running this script to get rfxcharts updatet in hstouch:
Sub Main(Optional ByVal pParms As String = "")
'This script is used to force refresh of
'RFXCharts images by invoking the respective
'chart pages periodically - HSTouch then
'displays the up-to-date images with no further
'action needed.
Dim HourlyUtilityChartPage As String = "http://192.168.2.197:7777/RFXCharts/UtilityH.aspx"
Dim DailyUtilityChartPage As String = "http://192.168.2.197:7777/RFXCharts/UtilityD.aspx"
'Refresh Hourly Utility Chart Page
hs.URLAction(HourlyUtilityChartPage, "GET", "", "")
'Refresh Daily Utility Chart Page
hs.URLAction(DailyUtilityChartPage, "GET", "", "")
End Sub

With this script i get this error in the hslog:
19-12-2013 18:02:01 - Error - In URLAction GET: The remote server returned an error: (401) Unauthorized.
If i open http://192.168.2.197:7777/RFXCharts/UtilityH.aspx in the browser then everything works well
Why do i get an unauthorized error with the script?

I'm new to scripting so be nice;-)

Thanks
Greetings
Edwin