g_form.addOption() is not working inside GlideAjax callback function

[HoangT551406063]

I have a MRVS have a field have type is Select Box, in my onLoad client script have a callback function in GlideAjax to get question choice in order to add options to select box field. I tried to log the response and it working correctly. but when I call g_form.addOption() outside the callback function then the option is added correctly but when I tried to call it inside the callback function it is not working. Please help.

//old options is cleared before this line        
var optionAjax = new GlideAjax('scoped_app.script_include');
        optionAjax.addParam('sysparm_name', 'functionname');
        optionAjax.addParam('sysparm_question_id', varId);
        // g_form.addOption('value_select_box', choiceValue, choiceLabel); this line work correctly but the addOption line below is not
        optionAjax.getXMLAnswer(function(response) {
            var res = JSON.parse(response); //[{'option_value':'value', 'option_text':'text'}]
            for (var i = 0; i < res.length; i++) {
                var choiceValue = res[i].option_value+'';
                var choiceLabel = res[i].option_text+'';
                g_form.addOption('value_select_box', choiceValue, choiceLabel);
//I also tried g_form.addOption('value_select_box', choiceValue, choiceLabel, i+1); but still not working
            }
        });

[Ankur Bawiskar]

@HoangT551406063 

share the variable config screenshots.

that variable should be of type Select box and I hope the choice values you are adding are already there in question_choice for that variable?