asp may drive help

I am using asp on IIS, have file upload function
but I dont want to keep those files in this server
so i going to map a network drive to a file server to store
but the problem happen here.
If i map drive in server, IIS is "Permission denied" to do this
so i try to use asp to map the network drive......
set ws1 = Server.CreateObject("WScript.Network")
ws1.MapNetworkDrive "T:","\\ip",false,"username","pw"
this is ok once, but time pass will lost connection and cant to fix back
open and close the drive each time is ok, but not sure if someone is opening fil
es with other adding files with same time...

thanks for reply