function newWindowCentered(winUrl, winName, winWidth, winHeight, winExtraAttr) {
	var scrWidth = window.screen.availWidth;
	var scrHeight = window.screen.availHeight;
	var winLeft = parseInt(scrWidth/2) - parseInt(winWidth/2);
	var winTop = parseInt( (parseInt(scrHeight/2) - parseInt(winHeight/2)) *0.6 );
	var winAttr = 'height=' + winHeight+ ',width=' + winWidth+ ',top=' +winTop+ ',left=' + winLeft
	if (winExtraAttr != '') {
		winAttr = winAttr + ',' + winExtraAttr;
	} else {
		winAttr = winAttr + ',' + 'toolbar=no,menubar=no,scrollbars=no,resizeable=no,location=no,directories=no,status=no';
	}
	var winNew = window.open(winUrl, winName, winAttr);
}