body 
{
   background-color: Navy;

}

#header
{
   width:100%;
   height:150px;
   background-color:Gray;
}

#content
{
   min-height:600px;
   width:100%;
   background-color:Red;
}

#left-column
{
   position:relative;
   float:left;
   width:200px;
   height:500px;
}

#middle-column
{
   position:relative;
   float:left;
   margin-left:20px;
   width:580px;
   height:500px;
}

#right-column
{
   position:relative;
   float:right;
   width:200px;
   height:500px;
}
#footer
{
   width:100%;
   height:50px;
   background-color: Yellow;
}