Execute Applescript in Automator: fails when running Automator action

Question

I am trying to get a simple Automator action to switch spaces every so often. I'm following directions found on MacScripter. The Applescript runs and works on it's own, or when I run the applescript from inside the Execute Applescript window of Automator. But when I run the automator action, the Execute Applescript action fails. Here's the Applescript code I've entered into the Execute Applescript window:
tell application "System Events"
keystroke "2" using control down
end tell
Again, this runs and does what it should if I click the Run button in the Execute Applescript window of the automator action. It fails when I run the whole automator action. This Execute Applescript is the first action in the automator sequence.
What am I missing?
Thanks!

Answer 1

Are you using the Run AppleScript action's run handler? The parameters are used to connect the action to Automator:
<pre style="
font-family: Monaco, 'Courier New', Courier, monospace;
font-size: 10px;
margin: 0px;
padding: 5px;
border: 1px solid #000000;
width: 720px;
color: #000000;
background-color: #FFDDFF;
overflow: auto;"
title="this text can be pasted into an Automator 'Run AppleScript' action">
on run {input, parameters}
tell application "System Events"
keystroke "2" using control down
end tell
return input
end run
</pre>