Applescript escape XML special chars

gistfile1.applescript

on escapeString(toEscape)
	set res to replaceChars(toEscape, "\"", """)
	set res to replaceChars(res, "'", "'")
	set res to replaceChars(res, "&", "&")
	set res to replaceChars(res, ">", ">")
	set res to replaceChars(res, "<", "&lt;")
	return res
end escapeString

on replaceChars(this_text, search_string, replacement_string)
	set AppleScript's text item delimiters to the search_string
	set the item_list to every text item of this_text
	set AppleScript's text item delimiters to the replacement_string
	set this_text to the item_list as string
	set AppleScript's text item delimiters to ""
	return this_text
end replaceChars