var NewWindow=null;

function ShowPage(PageFile,Width,Height) { 

	var WinLeft=Math.floor((screen.width-Width)/2);
    var WinTop=Math.floor((screen.height-Height)/22);

	var WinAppearence = 'menubar=yes,scrollbars=yes,width='+(Width)+',height='+(Height)+',top='+WinTop+',left='+WinLeft;

	NewWindow=window.open( PageFile,'NewWindow',WinAppearence);
	NewWindow.focus();

}