1 - Evita usar posicionamiento absoluto, baja puntos en accesibilidad ademas de que te estropea todo el layout si no sabes usarlo.
2 - Como tip, siempre ponle el ultimo punto y coma a los codigos, asi si tienes que agregar algo no te pierdes por que no te acuerdas que te falta el punto y coma.
entre otras cositas que tienes que arreglar, modifique el css completo, tenias mucho codigo innecesario, por ejemplo, no es necesario usar top y left en todos los selectores, mejor usa float para posicionar. Checka el codigo y dejanos saber en que parte tienes duda.
Cita: <!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>
<meta http-equiv="content-type" content="text/html;charset=iso-8859-1"/>
<title>prueba1</title>
<style type="text/css" media="screen">
body { color: #000;
background-color: #666;
margin: 0;
padding: 0;
}
#contenedor {
background-color: #fff;
position: relative;
width: 760px;
height: 100%;
min-height: 100%;
border-right: 1px solid #666;
border-left: 1px solid #666;
}
#cabecera {
background-color: #f66;
float: left;
width: 760px;
height: 90px;
}
#menuizquierdo {
background-color: #fc0;
float: left;
width: 170px;
}
#menuderecho {
background-color: #cf9;
float: right;
width: 150px;
}
#textocentral {
background-color: #9cf;
float: left;
width: 440px;
}
</style>
</head>
<body >
<div id="contenedor">
<div id="cabecera"></div>
<div id="menuizquierdo"></div>
<div id="menuderecho"></div>
<div id="textocentral">
<p>Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain Twenty years from now you will be more disappointed by the things that you didn t do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain
</p></div>
</div>
</body>
</html>>