Storing Element References As Public Object Members

I've spent several days trying to work this out. Maybe I'm just
searching for the wrong keywords/phrases.

I have some code that looks like:

[-- snippet starts --]
Console = new Object();
Console.init = function() {
this.STDIN = document.getElementById('console0_stdin');
this.STDOUT = document.getElementById('console0_stdout');

// set styles on the element references, eg:
this.STDIN.style.width = ï`%'
this.STDOUT.style.width = ï`%'
}

Console.focus = function() {
this.STDIN.focus();
}

Console.writeln = function(buffer) {
this.STDOUT.value += "
" + buffer;
}

[-- snippet ends --]

I'm not sure why, but the Console.focus() and Console.writeln() methods
just don't seem to be able to use the DOM references stored in
Console.STDIN and Console.STDOUT. Everything's fine in the
constructor, but other methods can't seem to use them.