The language of Advantech WebAccess scripts is derived from TCL, a scripting language commonly used for hardware-control programs.  Tcl is an open source language; you can find examples and tutorials on the Internet.  It is taught at many colleges and universities. It is the If, THEN, ELSE of Advantech WebAccess.  All KEYWORD commands are based on the Tcl programming language.  The Advantech WebAccess enhancements to Tcl are referred to as ACTION commands.  A typical TCL script will include both KEYWORD command and ACTION commands.

The KEYWORD commands follow are essentially identical to version 8.4 of other Tcl implementations.  For a description of the major differences, please see What's Different in Advantech WebAccess vs. other Tcl in Section 12.2.1