<input type="button" value="改变颜色"  onclick="changeColor()">  
    <input type="button" value="改变宽高"  onclick="changeW_H()">
    <input type="button" value="隐藏内容"  onclick="noneContent()">
    <input type="button" value="显示内容"  onclick="displayContent()">

    <input type="button" value="取消设置" onclick="setRest()">

var conChar = document.getElementById("con");
  var txtChar = document.getElementById("txt");
  var color = conChar.style.color;
  var width = conChar.style.width;
  var height = conChar.style.height;
  var dis = conChar.style.display;
//定义"改变颜色"的函数
    function changeColor(){
        conChar.style.color="red";
    }

//定义"改变宽高"的函数
    function changeW_H(){
        conChar.style.width = "1000px";
        conChar.style.height = "20px";
    }

//定义"隐藏内容"的函数
    function noneContent(){
        txtChar.style.display = "none";
    }

//定义"显示内容"的函数
    function displayContent(){
        txtChar.style.display = "block";
    }

//定义"取消设置"的函数
    function setRest(){
        var sign = confirm("确定取消设置？");
        if(sign) {
            conChar.style.color = color;
            conChar.style.width = width;
            conChar.style.height = height;
            txtChar.style.display = dis;
        }
        
    }