WinJS.Namespace.define with Form elements work around.

gistfile1.js

// assuming element with submitID is an input or button element
// work around 1
WinJS.Namespace.define("ui", {
    submit : null
});

ui.submit = document.getElementById("submitID");


// work around 2
WinJS.Namespace.define("ui", {
    dom : {
        submit : document.getElementById("submitID")
    }
});