最小高度设置

Below is the CSS code that makes your sticky footers actually stick to the bottom.

html, body {height: 100%;}

#wrap {min-height: 100%;}

#main {overflow:auto;
	padding-bottom: 150px;}  /* must be same height as the footer */

#footer {position: relative;
	margin-top: -150px; /* negative value of footer height */
	height: 150px;
	clear:both;} 

/*Opera Fix*/
body:before {
	content:"";
	height:100%;
	float:left;
	width:0;
	margin-top:-32767px;/
}

And on your html page you will need this conditional style for IE6 and earlier and for IE8 (!IE7 means not 7, but all others);

<!--[if !IE 7]>
	<style type="text/css">
		#wrap {display:table;height:100%}
	</style>
<![endif]-->

You'll notice that the footer height is used three times. This is important and should be the same value for all three instances. The height properties are stretching the wrap <div> to the full height of the window. The negative margin of the footer brings it up into the padding created for the main <div>. Since the main rests inside the wrap the padding height is already part of the 100%. Thus the footer rests at the bottom of the page.

The conditional statement is neccessary to allow IE8 to expand beyond the 100% height should the content be longer. The other hack is for browsers that dont understand min-height, in particular Opera. It uses a 100% height float to resize pages properly when adjusting the viewport (browser window) size. The -32767px margin is Opera's limit.