Can't make agsAdmin.exe run

hi,
I'm try to start arcgis 10.1 services using agsAdmin.exe but can't get it right.
username:abcde
password:12345
server:localhost
so i run c:\Task>agsAdmin.exe localhost 6080 abcde 12345 start SampleWorldCities.MapServices then i get:

Failed to get token
Failed to login, invalid username or password

Thank