web email with attachment

Been reading this article -

http://www.sitepoint.com/article/sending-web-email-asp-net/
** if there is a better one let me know.
But I wanted to know how I could also attach an attachment through the backend (vb) to the email. Basically I will have a button to display pdf file, and a button to email the pdf file. On click I want them to go to a small form. Where they put in subject, return address, to address, and body of email. On send the PDF file from the previous page will attach as it goes.
Any help would be great. Thanks.
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