The W3C HTML standard includes support for client-side scripting.It defines how locally executable scripts may be used in a web page.A particular client-side application, such as a web browser, may support several script languages.Script code may be executed as the document loads or at a later time. The W3C HTML standard includes support for client-side scripting.It defines how locally executable scripts may be used in a web page.A particular client-side application, such as a web browser, may support several script languages.Script code may be executed as the document loads or at a later time.