var myString = '<style type="text/css">';
for(i=1;i<30;i++){
	myString += '#item'+i+'{display:none;}';
}
myString += '</style>';
document.write(myString);

function openThis(myPage){
		var myWidth = 600; var _width = 0; var centered_width = 0; _width = screen.availWidth;
		var myHeight = 460; var _height = 0; var centered_height = 0; _height = screen.availHeight;
		if (_width>myWidth) centered_width = (_width-myWidth)/2;
		if (_height>myHeight) centered_height = (_height-myHeight)/2;
		viewer = window.open(myPage,"viewer","top="+centered_height+",left="+centered_width+",status=yes,scrollbars=yes,menubar=no,resizable=yes,width="+myWidth+",height="+myHeight);
		viewer.focus();
}