Form Submit Filter - Very Basic - VB.Net

GOAL: Develop a simple web-form filter that checks for illegal characters, invalid fields, and spam keywords (maybe 5 or so words hard coded) to reduce the spam received by customers. If a bad form submit is recognized, the system will skip the 'email customer' step, but still log the email to the database (this is already working). Code is written on a Microsoft IIS server using a custom CMS. Code does NOT compile on a local computer - only runs on a server environment. Code is written in VB.Net. NOTE: Code is VB.Net but is written in the style of the older Microsoft .asp pages.