Float

prosim poradte mi,ked nastavujem v css float tak ked dam na stred right,tak je stred nalepeny na pravej tab.ak dam left tak zasa opacne a ak dam none tak je sice v strede ale zasa laa tab je uplne inde,respektive dole,prosim ak urobim to ze mi to bude peke sediet ako ma?
tu je css

body {
background-color: white;
text-align: center;
margin-bottom: 1cm;
margin-top: 1cm;
margin-left: 1cm;
margin-right: 1cm;
}




#lavy {
display: block;
float: left;
clear: left;
width: 20%;
background-color: White;

}


#pravy {
display: block;
float: right;
clear: right;
width: 20%;
background-color: White;
font-family: sans-serif;

}


#stred {
display: block;
text-align: justify;
float:right;
width: 60%;
background: white;
}






#stred.kurz2{
background-image: url(../Linkin/pic/logo.jpg);

}


#table,td {
background-color: white;
color: black;
font-family: serif;

}
td.kurz {
background-color: #0099cc;
color: white;
font-family: serif;
}

table, td { border-color: black;
}


B { font-family: Arial CE,Helvetica CE,Arial,Helvetica, sansserif; font-size: 3.5mm;
}
h2{
color:#cc3399;
}
h4{
color:#0099cc;
}


li{
font-family: fantasy;
font-size: medium;
}

a:hover {color:#0099cc;
}

no nepomohlo to,ked som dal na stred float:left; tak bol zasa na lavo a lava tabulka bola az pod nim,