Issue with Zurich Version

Below onChange Client script is working in yokohoma but not in zurich, can someone please help me to understand on what is the issue?

function onChange(control, oldValue, newValue, isLoading) {

    if (isLoading || !newValue)
        return;

    var proceed = confirm("Please confirm");

    if (!proceed) {

        var ga = new GlideAjax('ScriptIncludeName');
        ga.addParam('sysparm_name', 'Function');
        ga.addParam('sysparm_abc', g_form.getValue('fieldname'));
        ga.getXML(function() {
            g_form.setValue('fieldname', '');
            g_form.reload();
            g_form.showFieldMsg(fieldname, 'cleared.', 'error');
        });
    }
}

@Ankur Bawiskar  @Its_Sagnic @Matthew_13