What is this JS???? [Resolved]

[NoteMe]

I am fixing the HTML and CSS at a page for a friend of my that he have made in DreamWeaver.

And DW have added some JS. What does it do...? Is it necessary to have it at all?

<script language="JavaScript" type="text/JavaScript">
		<!--
			function MM_reloadPage(init) {  //reloads the window if Nav4 resized
  			if (init==true) with (navigator) {if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
    				document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }}
  			else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
			}

			MM_reloadPage(true);
		//-->
		</script>

Is it some reload function if the browser changes size or something?