applescript allows to insert custom text in any os x app

gistfile1.scpt

-- 'selection' work in Pages.app only

tell application "Pages"
	set selText to selection
end tell
tell me
	activate
	display dialog "Type a tag" default answer ""
	set the_text to the text returned of result
end tell
set the clipboard to "<" & the_text & ">" & selText & "</" & the_text & ">"
tell application "System Events"
	tell application "Pages" to activate
	tell process "Pages" to key code 9 using command down
end tell