erasing files in list

I’m writing a script to erase everyone but two of the files that are downloaded into a folder.
Eratic things seem to happen. File names letters are rearranged and the script doesn’t know what to do if it is not sensing a file it’s looking for.
why should this matter? any way to improve the code and make it more stable?

set erasingfiles to {"spacer.gif", "home.gif", "shows.gif", "search.gif", "listen.gif", "about.gif", "powellsy120b.gif", "Peabody_Statuette.gif", "title.gif", "logo_pr.gifi", "logo_wpr_130w.jpg", "logo_xmradio.gif", "real1.gif", "arrow.gif"}
set filePath to (path to music folder as Unicode text) & "Audio Hijack:paparimage:pageimages:"
set thelist to list folder filePath


set item_num to my erasethefiles(erasingfiles, thelist)

on erasethefiles(this_item, this_list)
	repeat with i from 1 to the count of this_list
		repeat with j from 1 to the count of this_item
			if item i of this_list is item j of this_item then
				set filename to item i of this_item
				tell application "Finder"
					set file_path to (path to music folder as Unicode text) & "Audio Hijack:paparimage:pageimages:" & filename as string
					delete file file_path
					
				end tell
				
			end if
		end repeat
		
	end repeat
end erasethefiles

Hi,

set erasingfiles to {"spacer.gif", "home.gif", "shows.gif", "search.gif", "listen.gif", "about.gif", "powellsy120b.gif", "Peabody_Statuette.gif", "title.gif", "logo_pr.gifi", "logo_wpr_130w.jpg", "logo_xmradio.gif", "real1.gif", "arrow.gif"}
set filePath to (path to music folder as Unicode text) & "Audio Hijack:paparimage:pageimages:"
tell application "Finder" to delete (get files of folder filePath whose name is in erasingfiles)

PS: in this line

set file_path to (path to music folder as Unicode text) & "Audio Hijack:paparimage:pageimages:" & filename as string

the coercion at the end is useless, because the text class should be Unicode text.
If text is concatenated, AppleScript takes the class of the first text item and tries to coerce the others to this class