function re(){
var mychar=confirm("是否取消設置");
if(mychar==true){
var my=document.getElementById("txt");
my.removeAttribute("style");
}
else{
}//定義"取消設置"的函數
}
var mychar=document.getElementById("txt");
function gback(){
var char=confirm("do you want to reset all setting");
if (char==true){
mychar.className = "txt";
mychar.removeAttribute(‘style');
}
}