...though he can definitely answer it :)

Dijit (the widget system, which based on your post seems to be what you are interested in) is a JavaScript library. The fact of the matter is that we primarily feature HTML-based instantiation on this site (which is what an awful lot of people seem to be interested in), but any Dijit should be create-able via either markup or via JS. For example:

var w=new dijit.Menu({
    // params
}, someNode);

...will create an instance of a Dijit Menu, using some DOMNode as the node in which to create the Dijit.

One of the things that seems confusing to a lot of people though is that we do our best to maintain some version of "degradable" or "unobtrusive" coding practices; because of this, our general attitude is that you should leverage what is available with HTML as much as possible, and use libraries like Dijit to augment (as opposed to replace).

Hope that helps.

I'm not Alex, but I'm not sure I understand your concerns about Dojo HTML templates.

Dojo's ability to connect an HTML template with a js widget class is a huge advantage over Ext IMO. You can easily associate DOM elements of the HTML template to attributes of the widget class. Also, you can associate DOM event callback to methods of the class. In addition, the templates can support substitutes and embedded widgets, which become attributes of the js widget class. I looked briefly at Ext, but I couldn't find this capability.

I think the question isn't about using HTML templates, although that is an advantage over using Ext. Rather, I think tuxhero is wondering how to use Dojo to create a form solely via JavaScript, instead of embedding info into HTML tags. This is certainly possible -- as ttrenka answered this is a pretty common way to use the library.

You may want to look at the manipulating widgets through code section of the Dojo book.

See this link n sources code of that example.
http://extjs.com/deploy/dev/examples/form/xml-form.html

It's related to HTML Templete in dijit.

something like:

var form = new dijit.form.Form({
  id:"theForm"
});
dojo.body().appendChild(form.domNode);

var inp = new dijit.form.TextBox({
   value:"username"
});

form.appendChild(inp.domNode);

var button = new dijit.form.Button({
    label:"Submit",
    type:"submit"
});

form.appendChild(button.domNode);

dojo.connect(form,"onSubmit",function(e){
    var data = dijit.byId("theForm").getValues();
    dojo.xhrPost({ url:"foo.php",
        content: data,
        load: function(response){
            // callback response text
        }
});

admittedly, it's not as simple as the Form class of ext having things like .addButton() methods, but all of the components are available (and a11y accessible out of the box) and also allow you to do the markup equilivant:

Submit
    
         dojo.stopEvent(e);
         dojo.xhrPost({ url:"some.php", content: dijit.byId("theForm").getValues() });