Object Constructor

<div id="form_container" style="width:280px;height:250px;"></div>

var formStructure = [
    {type:"radio", name:"color", value:"r", checked:true, label:"Red"},
    {type:"radio", name:"color", value:"g", label:"Green"},
    {type:"radio", name:"color", value:"b", label:"Blue"}
];
var dhxForm = new dhtmlXForm("form_container", formStructure);

Parameters:

form_container - the id of the container specified before (instead of id, you can directly specify a container object there);
formStructure - the variable that contains definitions of form structure (form's controls, their attributes and position).

In order to learn available form's controls refer to the article "List of Controls".