Dropdown Menu Auto Insert Option

[Rookie]

I would like to create a new form and don't know how to accomplish it.
Basically, when I compose a new message I want a dropdown menu to be
available with these options: Informational;Official;To Be Filed
When I select each option, I would like an Auto Insert to occur, for example:
I select "Informational" from the dropdown menu and automatically a Header
and Footer is inserted to say this: "This email is for Information purposes
only"
I only need help creating the functions, my sysadmins can help me publish
the form.
Can this be accomplished?
Thank you

 

[Rookie]

I found a way to edit the code on the form to do what I need. Here is a
sample:

Function Item_Send()
NewText = ""
MyStatement = Item.UserProperties("Statement")
Select Case MyStatement
Case "Informational"
NewText = "This email is for Information purposes only"
End Select
Body = NewText & chr(13) & Body & chr(13) & NewText
End Function