I made this chat spammer awhile back, here you go.
It is made in Notepad++
Code:
set shell = createobject("wscript.shell")
strtext = inputbox("Message :")
strtimes = inputbox("Number of times to spam")
if not isnumeric(strtimes) then
wscript.quit
end if
msgbox "U have 3 seconds to get to your inputbox"
wscript.sleep( 3000 )
for i=1 to strtimes
shell.sendkeys(strtext & "{enter}")
wscript.sleep(500)
next