比较平滑的js控制textaera的高度

佐佐制造 --textarea---addheight

/* Reset style */
* { margin:0; padding:0; word-break:break-all; }
body { background:#FFF; color:#333; font:12px/1.4em Helvetica, Arial, sans-serif; }
h1, h2, h3, h4, h5, h6 { font-size:1em; }
a { color:#333; text-decoration:none; }
a:hover { text-decoration:underline; }
ul, li { list-style:none; }
fieldset, img { border:none; }
input, textarea, select, button { font:12px Helvetica, Arial, sans-serif; }
.button { padding:0 10px; height: 22px; border: 1px solid; border-color: #EEE #999 #999 #EEE; background: #DDD; color: #333; line-height: 20px; cursor: pointer; margin-left:2px; }
.submit { padding:0 10px; height: 22px; border: 1px solid; border-color: #DDD #CC8305 #CC8305 #DDD; background: #FFA200; color: #FFF; line-height: 20px; letter-spacing: 1px; cursor: pointer; }
/* edit style */
#edit { width:300px; margin:50px; }
.edit_caption { width:100%; overflow:hidden; margin-bottom:1px; overflow:hidden; }
.edit_caption span { display:block; float:left; margin:0 1px; padding:4px 10px; background:#DDD; cursor:pointer; }
.edit_caption span:hover { background:#EEE; }
#edit textarea { width:300px; height:80px; margin:0; padding:0; }

var addH=1;
function addHeight() {
if (!document.getElementById('comment_content')) return flase;
var comment = document.getElementById('comment_content');
var nowH = parseInt(comment.style.height);
if (nowH 25){
addH=1;
} else {
window.setTimeout("addHeight()","10");
}
}
}
function minHeight() {
if (!document.getElementById('comment_content')) return flase;
var comment = document.getElementById('comment_content');
var nowH = parseInt(comment.style.height);
if (nowH > 50) {
nowH-=2;
comment.style.height=nowH+"px";
addH++;
if (addH > 25){
addH=1;
} else {
window.setTimeout("minHeight()","10");
}
}
}

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