IE版本的判断

var Sys = {};
var ua = navigator.userAgent.toLowerCase();

var s;
(s = ua.match(/msie ([d.]+)/)) ? Sys.ie = s[1] :
(s = ua.match(/firefox/([d.]+)/)) ? Sys.firefox = s[1] :
(s = ua.match(/chrome/([d.]+)/)) ? Sys.chrome = s[1] :
(s = ua.match(/opera.([d.]+)/)) ? Sys.opera = s[1] :
(s = ua.match(/version/([d.]+).*safari/)) ? Sys.safari = s[1] : 0;

if (Sys.ie != null || Sys.ie != undefined) {
    //去掉页眉和页脚     
    pagesetup_null();
    // wb.execwb(7, 1);
}