## Overview This function executes the specified process when an event occurs in a monitored item. ## Syntax ##### JavaScript ``` $p.on(<Event name>, <Monitoring item>, <Optional action>) ``` ## Description Of Each Parameter |Parameter name|Description| |:--|:--| |Event name|Ajax event name| |Monitoring item|[Column name in database](dev-column-name) of the target item| |Optional processing|Processing when the event is fired| ## Example ##### JavaScript ``` $p.on('change', 'ClassA', function () { console.log('The value of Classification A has been changed.') }) ```