function open_imageroom(url, name, option) {
    if (typeof option == 'string' || option instanceof String) {
        var opts = option.split(',');
        if (!option.match(/scrollbars/i)) {
            opts.push('scrollbars=yes');
        }
        if (!option.match(/resizable/i)) {
            opts.push('resizable=yes');
        }
        if (!option.match(/width/i)) {
            opts.push('width=900');
        }
        option = opts.join(',');
    }

    var w = window.open(url, name, option);
    if (navigator.userAgent.indexOf('AppleWebKit/') > -1) {
        // Safari¤ÈChrome¤À¤±
        w.blur();
    } 
    w.focus();
}