Service Asking For Password

[shacho]

I have created a service with Automator to zap (rm -r) selected files and folders.
It works, but it asks me for my password when I use it.
Is there some way to eliminate this authentication step?

Here is the service workflow script:
on run {input, parameters}
repeat with anItem in input
set anItem to quoted form of POSIX path of anItem
do shell script "rm -r " & anItempassword "MyPassword" with administrator privileges
end repeat
end run

Here is the message Automator pops up when I run it:
Automator Runner wants to make changes.
Type your password to allow this.