4-1编程挑战
function change_color(){
var ch_object = document.getElementById("txt");
ch_object.style.color="red";
}
function ch_w(){
var ch_ws = document.getElementById("txt");
ch_ws.style.width="300px";
}
function ch_yc(){
var ch_ycs = document.getElementById("txt");
ch_ycs.style.display="none";
}
function ch_xs(){
var ch_xss = document.getElementById("txt");
ch_xss.style.display="block";
}
function ch_reset(){
var ch_reset = document.getElementById("txt");
var qd = confirm("确定取消吗?");
alert(qd);
if(qd==true){
ch_reset.removeAttribute("style");
}
else{
return;
}
}