To check for Cross site scripting vulnerabilities, use a Web Vulnerability Scanner. A Web Vulnerability Scanner crawls your entire website and automatically checks for Cross Site Scripting vulnerabilities. It will indicate which URLs/scripts are vulnerable to these attacks so that you can fix the vulnerability easily. Besides Cross site scripting vulnerabilities a web application scanner will also check for SQL Injection & other web vulnerabilities. Acunetix Web Vulnerability Scanner scans for SQL injection, Cross site scripting, Google hacking and many more vulnerabilities.