Force A Document To Load At The Top Level

I've got a document that I want to ensure always get loaded into the
top level document and not into a frame or iframe. I've got it figured
out how to detect if the document is loaded into a frame. But what I
want to happen is the HTML content in the iframe to be displayed in the
top level document w/o a return trip to the server.

Here's what I'm thinking:

function forceTopLevelDocument() {
if (top != self) {
//load the HTML from child document into parent document
//without a return trip back to the server
}
}

What I can't figure out is how to take the document loaded into a child
frame and push it's contents up into a parent frame.