That's Dreamweaver code (tip: the MM_ in the function name does not stand for Mickey Mouse
It's sort of a legacy feature that reloads the page for Netscape 4 browsers. This type of browser had an annoying bug that caused it not to redraw the layout if the browser had been resized under certain (don't ask me which) circumstances. Usually a reload was a counter-measure.
If you don't target NN4, then you can safely remove this code snippet.