I won't go into a lengthy article, but essentially out of sanity preservation I developed a universal (reusable) GlideAjax script include that does the following:

1. Allows the developer to pass any table as a parameter
2. Allows the developer to pass an encoded query for that table
3. Allows the developer to pass as many fields as they require
4. ...and the best part, within the field/variable parameter you can dot-walk to grab additional data

With these two scripts you shouldn't need to write another GlideAjax script include unless you have a unique circumstance.

Script Include

//JAXscript Script Include

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

    getStuff: function() {
        var vars;
        var dataset = [];
        var sysparmvars = this.getParameter('sysparm_variables');
        var variables = sysparmvars.split(",");
        var tbl = this.getParameter('sysparm_tbl');
        var qry = this.getParameter('sysparm_query');

        //apply the table and encoded query
        var rec = GlideRecord(tbl);
        var rec_qry = qry;
        rec.addQuery(rec_qry);
        rec.query();

        if (rec.next()){
            //setup variables   
            vars = {};
            var vr;
            var vr_ext;
            var new_vr;
            var vr_lbl;
            var dv;

            //loop through user provided variables array to 
            //generate object output
            for(i=0;i < variables.length;i++){

                //if the field name has a '-'
                if(variables[i].includes("-")){
                    var v = variables[i];
                    dv = v.toString();
                    vr = dv.split("-");
                    vr_lbl = v.replace('-','_');

                    //enable dot-walking here
                    //traverse the field name to dynamically 
                    //create object attributes

                    for(a=0;a < vr.length;a++){
                        vr_ext += "."+vr[a];                            
                    }

                    //dot-walking object is simple string
                    vr_ext = "rec"+vr_ext.replace(undefined,'')+".toString();";

                    //dot-walk string executed as code by 'eval' function
                    vars[vr_lbl] = eval(vr_ext);
                    vr_ext = undefined;

                }else{
                    //if the field name does not have '-'
                    vr = variables[i];
                    vars[variables[i]] = rec[vr].toString();
                }

            }

            //package the dataset
            dataset.push(vars); 
        }

        var json = new JSON();
        var data = json.encode(vars);//JSON formatted string
        return data;
    },

    type: 'JAXscript'
});

Client Script Example

//JAXscript Client Script


    //in 'sysparm_variables' you can dot-walk if you use '-'
    //ex1: manager-director-name will fetch the manager's director's displayed name
    //ex2: manager-director will return the manager's director's sysID
    //you can traverse any reference connection you normally can in GlideRecord
    //in 'sysparm_tbl' use any table you need
    //in 'sysparm_query' use an encoded query, set variables above it and mix those in as well

    var jax = new GlideAjax('JAXscript');
    jax.addParam('sysparm_name', 'getStuff');
    jax.addParam('sysparm_tbl', 'sys_user');
    jax.addParam('sysparm_query', 'employee_number=1234567');
    jax.addParam('sysparm_variables','name,u_vp-email,manager-name,u_director-name,location-country,location-latitude');
    jax.getXML(showMessage1);


    function showMessage1(response) {   
        var answer = response.responseXML.documentElement.getAttribute("answer");
        answer = JSON.parse(answer); //Transform the JSON string to an object

        //uses '_' instead of '-' for values
        g_form.setValue('name',answer.name);
        g_form.setValue('email',answer.u_vp_email);
        g_form.setValue('manager',answer.manager_name);
        g_form.setValue('director',answer.u_director_name);
        g_form.setValue('loc','Country: ' + answer.location_country + '    Lat: ' + answer.location_latitude);

    }