常用JS代码

// 移动设备侦测
var isMobile = {
  Android: function () {
    return navigator.userAgent.match(/Android/i);
  },
  BlackBerry: function () {
    return navigator.userAgent.match(/BlackBerry/i);
  },
  iOS: function () {
    return navigator.userAgent.match(/iPhone|iPad|iPod/i);
  },
  Opera: function () {
    return navigator.userAgent.match(/Opera Mini/i);
  },
  Windows: function () {
    return navigator.userAgent.match(/IEMobile/i);
  },
  any: function () {
    return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows());
  }
};

判断IE

  isIE: function (num) {
    var name = navigator.appVersion.toUpperCase();
    return num ? name.match(/MSIE (\d)/) && name.match(/MSIE (\d)/)[1] == num : /MSIE (\d)/.test(name);
  }

创建弹窗

function showMsg(msgContent){   
    var box = document.createElement("div");
    var msg = document.createElement("div");
    box.setAttribute("id", "showMsgBox");
    msg.setAttribute("id", "msgBox");
    with(box.style){
        position = "absolute";
        top = 0;
        left = 0;
        bottom = 0;
        right = 0;
        background = "rgba(255,255,255,.6)";
    }
    with(msg.style){
        margin = "0 auto";
        width = "500px";
        height = "400px";
        marginTop = "100px";
        padding = "55px";
        paddingBottom = "110px";
        fontSize = "30px";
        fontFamily = "微软雅黑";
        lineHeight = "40px";
        background = "#D1D1D1";
        borderRadius = "12px";
    }

    msg.innerHTML = msgContent || "空";
    box.appendChild(msg);
    document.body.appendChild(box);
}

showMsg("内容")

按键

$("#textinput").keydown(function(e) {
    e.keyCode; // this value
});