pretekajúci JS

Príjemný večer,

môžete mi prosím niekto vysvetliť, prečo tento JS počíta okraj od okraja obrazovky a nie od okraja DIV-u? Funguje to rovnako v IE i FF. Ďakujem za pomoc.

<script language="JavaScript">
<!--

var int;

function hidemenus(exc)
{
clearInterval(int);
int = null;
for (id=1; id<=7; id++){
if (id != exc) document.all("mnui"+id).style.visibility = "hidden";
}
}

function outobject()
{
int = setInterval("hidemenus(20)",1000);
// ison=0;
}

function onheader(hID)
{
hidemenus(hID);
document.all("mnui"+hID).style.visibility = "visible"
}

function onobject()
{
clearInterval(int);
int = null;
}
//-->
</script>

HTML:
<table border="0" cellspacing="0" cellpadding="0" class="menuline">
<tr style="text-align: center; line-height: 24px">
<td><span id="i1" onmouseover="onheader('1');" onmouseout="outobject();" class="menulineitem">|&nbsp;o nás&nbsp;|</span></td>
<td><span id="i2" onmouseover="onheader('2');" onmouseout="outobject();" class="menulineitem">&nbsp;XXXXX&nbsp;|</span></td>
<td><span id="i3" onmouseover="onheader('4');" onmouseout="outobject();" class="menulineitem">&nbsp;XXXXX&nbsp;|</span></td>
<td><span id="i4" onmouseover="onheader('5');" onmouseout="outobject();" class="menulineitem">&nbsp;XXXXX&nbsp;|</span></td>
<td><span id="i5" onmouseover="onheader('6');" onmouseout="outobject();" class="menulineitem">&nbsp;XXXXX&nbsp;|</span></td>
<td><span id="i6" onmouseover="onheader('3');" onmouseout="outobject();" class="menulineitem">&nbsp;kniha návštev&nbsp;|</span></td>
<td><span id="i7" onmouseover="onheader('7');" onmouseout="outobject();" class="menulineitem">&nbsp;XXXXX&nbsp;|</span></td></tr>
</table>

... toto tá časť, čo preteká ....

<table border="1" class="menubox" id="mnui1" style="left: 5px" onmouseover="onobject();" onmousemove="onobject();" onmouseout="outobject();">
<tr><td><a href="uvod.html" target="_self">&nbsp;úvodná stránka&nbsp;</a></td></tr>
</table>

....
až
....

<table border="1" class="menubox" id="mnui7" style="left: 5px" onmouseover="onobject();" onmousemove="onobject();" onmouseout="outobject();">
<tr><td><a href="uvod.html" target="_self">&nbsp;XXXXX&nbsp;</a></td></tr>
</table>

habendorf
Sorry, tak tá tabulka

<table border="1" class="menubox" id="mnui1" style="left: 5px" onmouseover="onobject();" onmousemove="onobject();" onmouseout="outobject();">
<tr><td><a href="uvod.html" target="_self">&nbsp;úvodná stránka&nbsp;</a></td></tr>
</table>

peta
Vďaka za pomoc. Mal si úplne pravdu. Nemal som v CSS div-u menu zadefinované position:relative. Po doplnení to funguje OK a už to neuteká na okraj okna. Ešte raz vďaka za pomoc.