經常會有類似開關效果的按鈕，顯示隱藏
display.gif
<script>
var flag = true;
var getbox = document.getElementById("box");
var trigger = document.getElementById("trigger");
trigger.onclick = function(){
if(trigger.value == "隱藏"){
getbox.style.display = "none"
trigger.value = "顯示";
}else{
getbox.style.display = "block";
trigger.value = "隱藏";
}
/*if(flag){
getbox.style.display = "none";
flag = false;
}else{
getbox.style.display = "block";
flag = true;
}*/
}
</script>
一種是通過定義一個布爾值來判斷，另一種是通過變換按鈕的value來判斷，原理相似
