Locked (Read Only) on SEND/Email

Hello, I have Adobe Acrobat Professional 8 and Adobe LiveCycle 8. I have created several forms with LiveCycle and have posted the forms on a server for my group (user) to use to contact me with appropriate information... I'd like for the user to be able to complete the information on the form BUT once they press an Email button for the form to be sent, I'd like for the form to be Read-Only or LOCKED so that the receiver cannot change the information. Also, it seems that I should be able to "enable user rights" in LiveCycle 8, right now I am opening my form(s) in Acrobat 8 and setting that option. I am enabling user rights so that the person completing the form and the person receiving the form can save the form on their workstation. Thanks...