To get around the default .NET Web API GET calls (http://localhost:10305/api/ISS/?strUser=myusername&strPass=mypassword) where you only specify parameters and not the function name, add this code snippet to your Global.asax.vb file:
Public Shared Sub RegisterRoutes(routes As RouteCollection)
routes.MapHttpRoute(name:="DefaultApi", routeTemplate:="api/{controller}/{action}", defaults:=New With {Key .action = "get"})
routes.MapHttpRoute(name:="DefaultApi", routeTemplate:="api/{controller}/{action}", defaults:=New With {Key .action = "post"})
End Sub
Then you can make a call that looks like this:
http://localhost:10305/api/ISS/
LoginFunction?strUser=myusername&strPass=mypassword
This is just an example, don't ever send a username and password like this!