Is there anyway to see if there is an .EXE in a directory and if there is open it

i tried this
VB Code:
  1. If "C:\Program Files\MSN Messenger\msnmsgr.exe" = "" then
  2. Shell "C:\Program Files\MSN Messenger\msnmsgr.exe"
  3. Else
  4. Shell "C:\Program Files\Messenger\msmsgs.exe"
  5. End If

Thnks in advance Chris1990