Onchange client script parameters and use ServiceNow

onChange() client script runs when a particular field value changes on the form. The onChange() client script must specify these parameters.

• control: the DHTML widget whose value changed.
• oldValue: the value the widget had when the record was loaded.
• newValue: the value the widget has after the change.
• isLoading: identifies whether the change occurs as part of a form load.
• isTemplate: identifies whether the change occurs as part of a template load