How to launch Outlook Web Access (OWA) from Siebel

Hi,
There are examples in bookshelf to launch MS Office applications from Siebel.

/****
function Application_PreInvokeMethod (MethodName)
var iReturn = ContinueOperation;
switch (MethodName)
{
case "LaunchWord":
Clib.system("C:\\Program Files\\Microsoft Office\\Office\\WINWORD.EXE",1);
iReturn = CancelOperation;
break;
case "LaunchExcel":
Clib.system("C:\\Program Files\\Microsoft Office\\Office\\EXCEL.EXE",1);
iReturn = CancelOperation;
break;
case "LaunchOutlook":
Clib.system("C:\\Program Files\\Microsoft Office\\Office\\OUTLOOK.EXE",1);
iReturn = CancelOperation;
}
return (iReturn);
}

**********/

I want to launch Outlook Web Access from a button in Siebel.  How can I do that?

TIA