层自动适应高度

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"><head><title></title><style type="text/css"> 
body { 
font:12px Tahoma;margin:0px;text-align:center; 
} 
a:link,a:visited {font-size:12px;text-decoration:none;} 
a:hover{}

/*页面层容器*/ 
#container { 
width:780px;margin:0px auto;background:#fff 
}

/*页面头部*/ 
#header {background:url(logo.gif) no-repeat;}

#banner { 
    background:url(banner.jpg) 0px no-repeat; /*加入背景图片*/;background:#999; 
    width:780px; /*设定层的宽度*/ 
    margin:auto; /*层居中*/ 
    height:200px; /*设定高度*/ 
    border-bottom:5px solid #EFEFEF; /*画一条浅灰色实线*/ 
    clear:both /*清除浮动*/ 
} 
#pagebody { 
    width:780px; /*设定宽度*/ 
    margin:0px auto; /*居中*/ 
    background:#000 
} 
#sidebar { 
    width:200px; /*设定宽度*/ 
    text-align:left; /*文字左对齐*/ 
    float:left; /*浮动居左*/ 
    background:#f3c;color:#666

overflow:hidden; /*超出宽度部分隐藏*/ 
    
    height:300px; 
    padding:0px

} 
#mainbody { 
    width:580px; 
    text-align:left; 
     margin:0px auto; /*居中*/ 
     
  float:right;

overflow:hidden; 
     color:#fff

}

/*页面底部*/ 
#footer{ 
width:780px;margin:0 auto;height:65px;background:#999;repeat-x;color:#ff0066;clear:both; 
} 
</style></head><body> 
      <div id=container></div> 
<div id=header> 
<div id=banner></div></div> 
<div id=pagebody> 
<div id=sidebar><h2>这一层需要与右边的层同步,也需要自适应高度</h2></div> 
<div id=mainbody><h2>想使这一层自动适应高度,有办法吗?</h2></div> 
<div style="clear:both;height:1px;margin-bottom:-1px;padding:0; background:#FF0000"></div> 
</div> 
<div id=footer>这一层不变</div></div></body></html>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

层自动适应高度_经验交流