Sticky Footer, but only sometimes

I've got a basic site with header, content, footer. What I'm looking for is a way to style the footer so that, depending on screen resolution, if the content doesn't fill the page it sticks to the bottom, but if content overflows it pushes the footer down (have to scroll the browser to see the footer).

<div id="wrapper">
<div id="headwrapper">
<div id="header"></div>
    <div id="menu">
       <ul>
          <li class="active"><a href="#" title="Link1">Link1</a></li>
          <li><a href="#" title="Link2">Link2</a></li>
          <li><a href="#" title="Link3">Link3</a></li>
          <li><a href="#" title="Link4">Link4</a></li>
          <li><a href="#" title="Link5">Link5</a></li>
       </ul>        
    </div>
    <div id="content-container">
          <div id="content">
              <h2>
                  Page heading
              </h2>
              <p>
                  Lorem ipsum dolor sit amet consect etuer adipi scing elit sed diam nonummy nibh euismod tinunt ut laoreet dolore magna aliquam erat volut. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
              </p>
              <p>
                  Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi. Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.
              </p>
              <p>
                  Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi. Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat.
              </p>
          </div>
          <div id="aside">
              <h3>
                  Aside heading
              </h3>
              <div class="box">
              <p>
                  Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan.
              </p>
              </div>
              <div class="box">
              <p>
                  Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan.
              </p>
              </div>
          </div>
 </div>
</div>
<div id="footer">
 <p>Footer content</p>
</div>
</div>

html, body {height:100%;}

#wrapper {
    max-width:100%;
    min-width:1000px;
开发者_JAVA百科    min-height:100%;
    margin:0 auto;
 background-image:url(images/shadowborder.png);
 background-repeat:repeat-y;
 background-position:center;
}

#headwrapper {
 position:relative;
 -moz-background-clip:border;
 -moz-background-origin:padding;
 -moz-background-size:auto auto;
 background-attachment:scroll;
 background-color:#003a72;
 background:url(images/bnr_rpt.jpg) repeat-x;
 height:150px;
}

#header {
 position:relative;
 -moz-background-clip:border;
 -moz-background-origin:padding;
 -moz-background-size:auto auto;
 background-attachment:scroll;
 background-color:transparent;
 background:url(images/KMIAFS_banner.jpg) center top no-repeat;
 height:150px;
}

#menu {
 clear:left;
 float:left;
 padding:0;
 border-top:5px solid #f52620;
 width:100%;
 overflow:hidden;
 height:70px;
}


#menu ul {
 float:left;
 margin:0;
 padding:0;
 list-style:none;
 position:relative;
 left:50%;
 text-align:center;
}

#menu ul li {
 display:block;
 float:left;
 list-style:none;
 margin:0;
 padding:0;
 position:relative;
 right:50%;
 font-size:16px;
 font-family:Verdana, Geneva, sans-serif!important;
 font-weight:bold;
}

#menu ul li a {
 display:block;
 float:left;
 margin:0 2px 0 0;
 padding:10px 20px 6px 20px;
 background:#003a72;
 text-decoration:none;
 color:#FFF;
}

#menu ul li a:hover {
 padding:15px 20px 6px 20px;
 background-color:#999;
}

#menu ul li.active a, #menu ul li.active a:hover {
  color:#CCC;
}

#content-container {
 min-height:100%;
 height:100%;
 height:auto!important;
 margin:0 auto -70px;
 width:1000px;
}

#content {
 clear:left;
 float:left;
 width:610px;
 margin:0 0 0 30px;
 display:inline;
 background-color:transparent;
}

#content img {
 border:solid 2px #CCC;
 float:left;
 margin:14px 10px 10px 0px;
}

#content h2 {
 margin:0;
}

#aside {
 float:right;
 width:290px;
 margin:0 30px 0 0px;
 display:inline;
 background-color:transparent;
}

#aside p {
 color:#CCC;
}

#aside .box {
 margin-bottom:20px;
 padding:20px;
 color:#fff;
 background-color:#336699;
 -webkit-border-radius:20px;
 -moz-border-radius:20px;
}

#footer {
 height:70px;
 width:100%;
 border-top:5px solid #f52620;
 background:url(images/ftr_rpt.jpg) repeat-x;
 text-align:center;
 color:#FFF;
 margin:0 auto;
 clear:both;
}

#footer a {
 color:#FFF;
 text-decoration:none!important;
 padding:-5px;
}

#footer a:hover {
 color:#CCC;
}

And here's the site: http://www.erisdesigns.net/Stage/McCampbellInsurance/index.html

I use this version, and it works quite well.