#contenido {
  width: 1100px;
}


#izda {
  float: left;
  width: 800px;
  border:1px solid #D3EAF3;  
}

#dcha {
  float: left;
  font:110% "Trebuchet MS", Tahoma, Arial;
  background:#FFF;
  width: 200px;
}

#debajo {
  float: left;
  font:90% "Trebuchet MS", Tahoma, Arial;
  background:#FFF;
  width: 1000px;
  clear:both;
}

#filtro {
  float: left;
  font:90% "Trebuchet MS", Tahoma, Arial;
  background:#FFF;
  width: 1000px;
  clear:both;
}