how to set a form field that automatically saves as email subject title

I am creating a form in acrobat 9 and want the submit to email button to automatically use the information from one of the text fields as the subject title of the email. So when the client submits the form at the end the PO number they have used will automatically be the email subject. Is there any way to do this? I have found an example created using javascript but I am very much a novice with this so I don't know where to start with this? Any help would be greatly appreciated Image may be NSFW.
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