微博输入字数代码如下：
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>03.微博输入字数</title><style type="text/css" media="screen">body{font-size:12px;}.box{width:600px;height:160px;border:10px solid pink;margin:10px auto;padding:10px;}img{float:left;width:190px;height:24px;}.box1{float:left;margin-left:255px;width:150px;height:24px;text-align:right;font-size:14px;color:#888;}.box1 span{font-size:16px;font-weight:bold;}#text{width:600px;height:100px;border:1px solid #888;margin-top:5px;}.box #sp1,#sp2,#sp3,#sp4,#sp5,#sp6{float:left;width:30px;height:32px;line-height:32px;padding-left:26px;}#sp1{background:url(../static/weibo/an5.png) no-repeat left center;}#sp2{background:url(../static/weibo/an4.png) no-repeat left center;}#sp3{background:url(../static/weibo/an3.png) no-repeat left center;}#sp4{background:url(../static/weibo/an2.png) no-repeat left center;}#sp5{background:url(../static/weibo/an1.png) no-repeat left center;width:40px;}#sp6{margin-left:150px;margin-right:15px;color:#888;}#bt{float:left;width:80px;height:30px;border:none;background:#ffc09f;color:#fff;border-radius:5px;}</style><script type="text/javascript">var text,number,bt,m;window.onload=function(){text=document.getElementById('text');number=document.getElementById('number');bt=document.getElementById('bt');text.onkeyup=function aa(){m=140-text.value.length;if(m<0){number.style.color="red";}else{number.style.color="#888";}number.innerHTML=m;}bt.onclick=function(){if(m>0&&m<140){// alert("您还没输入！！！");// text.focus();alert("发布成功！");}else if(m<0){alert("您输入的字数过多！！");text.focus();}else{alert("您还没输入！！！");text.focus();// alert("发布成功！");}}// aa();}</script></head><body><div class="box"><img src="../static/weibo/12.png"><div class="box1">还可以输入<span id="number"></span>字</div><textarea id="text"></textarea><span id="sp1">表情</span><span id="sp2">图片</span><span id="sp3">视频</span><span id="sp4">话题</span><span id="sp5">长微博</span><span id="sp6">公开</span><input type="button" value="发布" id="bt"></div></body></html>