How to edit writable locations in a document in Pages '09? The following image shows a region of the sheet it is not possible to write or select. There the cursor is, if i write another letter it will show up on the next page.

How do i enable the document to let me write on that field? I have tried dragging the side markers, but they only control how far down the reference text is.
You can change the page borders in the property sheet: