Ui Action not working in Workspace

[Rosy14]

Below code for Workspace Client Script not working:

Requirement: If parent case contain open child tasks, while closing the case it will show a pop-up and close parent along with child

function onClick() {

    if (!g_form.getValue("assigned_to")) {
        g_form.addErrorMessage('Assigned To cannot be empty. Please fill the Assign To field before moving the request to Awaiting Info or Resolved.');
        return false;
    }

    var close_notes = g_form.getValue("close_notes");
    var resolution_code = g_form.getValue("resolution_code");
    //var cause1 = g_form.getValue("cause");

    if (!close_notes || !resolution_code) {
        g_form.addErrorMessage(
            getMessage(
                'To propose a solution, you must select a resolution code and add resolution notes.'
            )
        );
        return false;
    }

    // First check if there are open tasks
    gaCheck = new GlideAjax("sn_customerservice.CheckTaskRecord");
    
    gaCheck.addParam('sysparm_name', 'checkIfTask');
    gaCheck.addParam('sysparm_request_id', g_form.getUniqueValue());
	g_form.addInfoMessage(g_form.getUniqueValue());
    gaCheck.getXMLAnswer(function(response) {
        g_form.addInfoMessage("Test2");
        var tasksAvailable = response;

        if (tasksAvailable == true) {
            g_form.addInfoMessage("Test1");
            if (!confirm("Resolution of request will close all open tasks. Do you want to proceed?")) {
                return;
            } else {
                gaCheck = new GlideAjax("sn_customerservice.CheckTaskRecord");
                gaCheck.addParam('sysparm_name', 'updateTaskRecord');
                gaCheck.addParam('sysparm_request_id', g_form.getUniqueValue());
                gaCheck.getXMLAnswer(function(response) {
                    var res = response;
                });
            }
        }
        g_form.setValue("state", "6");
        g_form.update();
    });
}

var CheckTaskRecord = Class.create();
CheckTaskRecord.prototype = Object.extendsObject(global.AbstractAjaxProcessor, {

    checkIfTask: function() {
        var parent = this.getParameter('sysparm_request_id');
        var taskGR = new GlideRecord("sn_customerservice_task");
        taskGR.addQuery("parent_case", parent);
        taskGR.addQuery("state", "!=", "3");
        taskGR.query();
        if (taskGR.hasNext())
            return true;
        else
            return false;
    },
    updateTaskRecord: function() {
        var parent = this.getParameter('sysparm_request_id');
        var taskGR = new GlideRecord("sn_customerservice_task");
        taskGR.addQuery("parent_case", parent);
        taskGR.addQuery("state", "!=", "3");
        taskGR.query();
        while (taskGR.hasNext()) {
            taskGR.setValue("state", "3");
            taskGR.setValue("work_notes", "Parent request has been resolved.");
            taskGR.update();
        }
		return true;
    },

    type: 'CheckTaskRecord'
});