var url = "https://www.baidu.com";

 var args = {};

 var swidth = 830;

 var sheight = 600;

 var sLeft = (window.screen.width - 830) / 2;

 var sTop = (window.screen.height - 600) / 2;

 window.showModalDialog(url, args, "dialogWidth=" + swidth + "px;dialogHeight=" + sheight + "px;status=no;help=no;scroll=yes;resizable=yes;minimize=yes;maximize=yes;");

 window.open(url, '打开百度', 'top=' + sTop + ',left=' + sLeft + ',height=' + sheight + ', width=' + swidth + ', toolbar=no, menubar=no, resizable=yes,location=no, status=no');