Problem with choose from list

I’m having a problem with my script when trying to choose from a list and then use if then statement to process a file if depending on what is selected. Simply stated, I want a user to select a publication from the list and then the script will process the file depending on what pub is selected. Here’s my script:

on open publish_file	
	repeat with a_file in publish_file
		set allPubs to {"Post Bulletin", "Austin Post Bulletin", "AgriNews", "AutoFinder", "REM", "PB Xpress"}
		set Pub to (choose from list allPubs with prompt "Please pick a publication.")
		display dialog Pub
		-- Post Bulletin
		if Pub = "Post Bulletin" then
			tell application "Finder"
				set file_Name to name of file a_file
				set folder_Name to folder of file a_file
				move a_file to folder "Publish:PostBulletin"
				display dialog "file moved to server"
				select folder_Name
				move selection to folder "Macintosh HD:PastFolders:Publish Files"
				display dialog "file moved to archive"
			end tell
			display dialog "file not moved."
		end if
	end repeat
end open

When ever I run this, it doesn’t do the lines for the “if then”, it goes to the “else” and does that. What am I missing? I thought this would have been fairly simple but I’m missing something.

Pub is a list of one item, so if Pub = “Post Bulletin” always fails, i.e. {“Post Bulletin”} ≠“Post Bulletin”.

You have to look at “item 1 of Pub” or “Pub as text” or “Pub as string”, or use “Pub = {“Post Bulletin”}” or Pub contains “Post Bulletin”

Display dialog coerces it to text - a logical test doesn’t.