<!doctype html><html><head><meta charset="utf-8"><title>無標(biāo)題文檔</title><script ?type="text/javascript">function yname(){? ?var obj=document.getElementById("Name");? ?var yourname=obj.value;? ?if(yourname!=null)? ? alert("你好!"+yourname);? ?else? ? alert("請輸入你的姓名！");}</script></head><body><form><p>姓名：<input type="text" id="Name" ></p><input type="button" value="確定" onclick="yname()" /></form></body></html>
為什么if else語句沒起作用？
木槿111
2017-05-24 15:47:13
