[css layout][07] three fixed columns

#container {
width: 900px;
margin: 0 auto;
}
#wrapper {
float: left;
}
#content {
margin: 0 200px;
}
#navigation {
width: 200px;
float: left;
margin-left: -100%;
}
#extra {
width: 200px;
float: left;
margin-left: -200px;
}
#footer {
clear: both;
}

#container {
width: 900px;
margin: 0 auto;
}
#wrapper {
float: right;
}
#content {
margin: 0 200px;
}
#navigation {
width: 200px;
float: right;
margin-right: -200px;
}
#extra {
width: 200px;
float: right;
margin-right: -100%;
}
#footer {
clear: both;
}

#container {
width: 900px;
margin: 0 auto;
}
#wrapper {
float: right;
width: 500px;
margin-left: -200px;
position: relative;
left: -200px;
}
#navigation {
width: 200px;
float: right;
margin-left: -400px;
position: relative;
left: -400px;
}
#extra {
width: 200px;
float: right;
margin-right: -300px;
}
#footer {
clear: both;
}

#container {
width: 900px;
margin: 0 auto;
}
#wrapper {
float: left;
width: 500px;
margin-right: -200px;
position: relative;
left: 200px;
}
#navigation {
width: 200px;
float: left;
margin-left: -300px;
}
#extra {
width: 200px;
float: left;
margin-right: -400px;
position: relative;
left: 400px;
}
#footer {
clear: both;
}