php reload page without posting data

I'm trying to refresh a page without sending POST from the previous time. I've tried ``` window.open("postme.php?r=t", "_self"); ``` Which appends a `?r=t` to the end but it doesn't appear to refresh the page as the page displays a number of files in a directory which hasn't change even though I have moved or deleted them. Can you specify the URL in `window.location.reload();`? Any ideas? Thanks