eccomi

codice:
<div id="menu_coop" style="position:absolute; width:145px; height:5px; left: 20%; top: 72px; visibility:hidden; margin-left:-180px;	filter:shadow(color=#666666, Direction=135);" onMouseOver="showmenu('menu_coop',1)" onMouseOut="showmenu('menu_coop',0)">

  <table width="145" height="30"  border="0" cellpadding="0" cellspacing="0" class="voci">
    <tr>
      <td width="145" height="10" onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Chi
        siamo </td>
    </tr>
    <tr>

      <td height="10" onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Contatti</td>
    </tr>
    
    <tr>
      <td height="10" onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Cooperazione
        sociale </td>
    </tr>
  </table>
</div>


<div id="menu_aree" style="position:absolute; width:145px; height:5px; left: 37%; top: 72px; visibility:hidden; margin-left:-214px;" onMouseOver="showmenu('menu_aree',1)" onMouseOut="showmenu('menu_aree',0)">
  <table width="100%" height="100%"  border="0" cellpadding="0" cellspacing="0" class="voci">
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'" onClick="document.location='areesviluppo.php#inclusione'">Inclusione
        sociale </td>
    </tr>
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'" onClick="document.location='areesviluppo.php#it'">Information
        technology </td>
    </tr>

    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'" onClick="document.location='areesviluppo.php#rs'">Ricerca
        e sviluppo</td>
    </tr>
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'" onClick="document.location='areesviluppo.php#com'">Comunicazione</td>
    </tr>
  </table>
</div>

<div id="menu_offriamo" style="position:absolute; width:145px; height:5px; left: 73%; top: 72px; visibility:hidden; margin-left:-218px;" onMouseOver="showmenu('menu_offriamo',1)" onMouseOut="showmenu('menu_offriamo',0)">

  <table width="100%" height="100%"  border="0" cellpadding="0" cellspacing="0" class="voci">
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Grafica</td>
    </tr>
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Outsourcing</td>
    </tr>

    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Progettazione
        europea</td>
    </tr>
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Consulenza</td>
    </tr>
    <tr>
      <td onMouseOver="this.style.background='#9299A0';this.style.cursor='pointer';this.style.color='#ffffff'" onMouseOut="this.style.background='#efefef';this.style.color='#000000'">Inserimento</td>

    </tr>
  </table>
</div>
io qui vedo delle tabelle, ma non vedo i dati tabellari (cioè in corrispondenza riga colonna).
inoltre, sotto si possono usare le classi per risparmiare un po' di codice (uguale):

codice:
	<div style=" width:287px; height:120px; position:absolute; background-color:#000000; top: 270px; left:33%; margin-left:-295px; background-image:url(images/cooperativa2.jpg); background-position:0px -10px;"  id="coopl" onMouseOver="roll('coopl','coop',1); this.style.cursor='pointer'" onMouseOut="roll('coopl','coop',0)" onClick="document.location='cooperativa.php'">
	</div>
	<div style="width:287px; height:120px; position:absolute; background-color:#000000; top: 400px; left:66%; margin-left:-289px;background-image:url(images/offer-home.jpg);background-position:0px -10px;" id="rassl" onMouseOver="roll('rassl','rass',1); this.style.cursor='pointer'" onMouseOut="roll('rassl','rass',0)" onClick="document.location='cosaoffriamo.php'">
	</div>
	<div style="width:287px; height:120px; position:absolute; background-color:#000000; top: 270px; left:100%; margin-left:-292px;background-image:url(images/lavoriamocon.jpg);background-position:0px -10px;" id="lavl" onMouseOver="roll('lavl','lav',1); this.style.cursor='pointer'" onMouseOut="roll('lavl','lav',0)" onClick="document.location='lavoriamo.php'">
	</div>
	
	<div style=" width:287px; height:120px; position:absolute; background-color:#000000; top: 400px; left:33%; margin-left:-295px;background-image:url(images/portfolio2.jpg);background-position:0px -10px;" id="portl" onMouseOver="roll('portl','port',1); this.style.cursor='pointer'" onMouseOut="roll('portl','port',0)" onClick="document.location='portfolio.php'">
	</div>
	<div style="width:287px; height:120px; position:absolute; background-color:#000000; top: 270px; left:66%; margin-left:-289px;background-image:url(images/aree.jpg);background-position:0px -10px;"  id="areel" onMouseOver="roll('areel','aree',1); this.style.cursor='pointer'" onMouseOut="roll('areel','aree',0)" onClick="document.location='areesviluppo.php'">

	</div>
	<div style="width:287px; height:120px; position:absolute; background-color:#000000; top: 400px; left:100%; margin-left:-292px;background-image:url(images/riservata.jpg);background-position:0px -10px;" id="risl" onMouseOver="roll('risl','ris',1); this.style.cursor='pointer'" onMouseOut="roll('risl','ris',0)" onClick="document.location='areariservata.php'">
	</div>

e visto che ci siamo, il menù è una lista, non una successione di link:

codice:
<div style="margin-top:55px; width:760px; float:left;">
	<a href="cooperativa.php" class="menu">la
	cooperativa</a> | <a href="areesviluppo.php" class="menu" onMouseOver="showmenu('menu_aree',1)" onMouseOut="showmenu('menu_aree',0)">aree
	di sviluppo</a> | <a href="lavoriamo.php" class="menu">lavoriamo
	con</a> | portfolio | <a href="cosaoffriamo.php" class="menu">cosa
	offriamo</a> | <a href="areariservata.php" class="menu">area
	riservata</a> | contattaci	</div>

· i script devono stare fra <head> e </head> o meglio ancora in un file esterno;
· le tabelle vanno usare per contenere dati tabellari, cioè in corrispondenza riga-colonna;
· le formattazioni sono compito esclusivo dei fogli di stile;
· è meglio non mescolare stili esterni e stili inline;

quindi prima di fare casino in privato.. controllare le proprio pagine. sì, sono poco gentile ma stai tranquillo che il tizio che mi dice "ho fatto questo sito nel tempo libero" non riceve le stesse risposte.