This script is dangerous because it does not properly quote special characters in the names of the to be deleted items. In particular it will not work correctly, and could potentially cause unwanted data loss, when used on items whose names contain the quotation mark. To correct this, replace

do shell script "rm -rf \"" & posixPath & "\""

with

do shell script "rm -rf " & quoted form of posixPath

and

do shell script "rm -rf ~/.Trash/\"" & selectedName & "\""

with

do shell script "rm -rf ~/.Trash/" & quoted form of selectedName

set frontAppPath to (path to frontmost application) as string

if the frontAppPath ends with ":Finder.app:" then
	tell application "Finder"
		set selectionList to get selection as list
		set selectedCount to count items in selectionList
		--Added code1
		display dialog "Do you really want to delete this item?" buttons {"OK", "Cancel"} default button 2
		if the button returned of the result is "Cancel" then
			return
		else
                --End of added code1
			if selectedCount > 0 then
				repeat with i from 1 to number of items in the selectionList
					set selectedItem to item i of the selectionList
					set selectedName to the name of selectedItem
					set homePath to (path to home folder) as string
					set trashPath to homePath & ".Trash:"
					set deletePath to trashPath & selectedName & ":"
					
					if not ((kind of selectedItem as string) is equal to "Volume") then
						if (selectedItem as string) contains ".Trash" then
							set posixPath to POSIX path of (selectedItem as string) as string
							do shell script "rm -rf "" & posixPath & """
						else
							try
								deletePath as alias
								display dialog "Error: file named "" & selectedName & "" already exists in the Trash."
							on error
								try
									tell application "Finder" to delete selectedItem
									do shell script "rm -rf ~/.Trash/"" & selectedName & """
								end try
							end try
						end if
					end if
				end repeat
			end if
                 --Added code2		
                 end if
                 --End of added code2
	end tell
end if

tell application "Finder"
	if frontmost is false then return
	set selectedList to the selection
	set deleteList to {}
	repeat with thisItem in selectedList
		if class of thisItem is not disk then
			set end of deleteList to thisItem
		end if
	end repeat
	delete deleteList
	ignoring application responses -- because secure deletes can take a while
		empty trash with security
	end ignoring
end tell

tell application "Finder"
	if frontmost is false then return
	set selectedList to the selection
	set deleteCmdList to {}
	repeat with thisItem in selectedList
		if class of thisItem is not disk then
			set end of deleteCmdList to quoted form of (POSIX path of (thisItem as alias))
		end if
	end repeat
end tell

set {tid, AppleScript's text item delimiters} to {AppleScript's text item delimiters, " "}
set cmd to deleteCmdList as text
set AppleScript's text item delimiters to tid
do shell script cmd