/*
* ポップアップウィンドウ（センター表示）
*/
function PopUp( url,windowname, width, height ) {
	var features="location=no, menubar=no, status=yes, scrollbars=yes, resizable=yes, toolbar=no";
	if( width ) {
		if( window.screen.width > width ) {
			features += ", left="+( window.screen.width - width ) / 2;
		}
		else {
			width = window.screen.width;
		}
		features += ", width="+width;
	}
	
	if( height ) {
		if( window.screen.height > height ) {
			features += ", top="+( window.screen.height-height ) / 2;
		}
		else {
			height = window.screen.height;
		}
		features += ", height="+height;
	}
	window.open( url, windowname, features );
}