You can define parameters for your XSL transformation when adding the XSL Transformation server behavior to a web page. A parameter controls how XML data is processed and displayed. For example, you might use a parameter to identify and list a specific article from a news feed. When the page loads in a browser, only the article you specified with the parameter appears.
Add an XSLT parameter to an XSL transformation
Edit an XSLT parameter
Delete an XSLT parameter