Set Message content in Apple Mail

I want to set the message body of the frontmost outgoing Mail message using AppleScript. In other words, if I hit the Reply button in Mail a new message is created already addressed to the recipient. All I want to do is set the content of this message.

Thanks.

Hi tfindlay

Not sure if this is what you need, you could do with giving a little more info…
like do you want to create the email from scratch, are you just wanting the script to run when you click reply(not sure if this can be done) etc… etc…
However this will fill the message with content:

tell application "Mail"
	activate
	make new outgoing message with properties {content:"Your message goes here!", subject:"", visible:true}
end tell