[Solved] Tabs style in FireFox 2.0.0.2

The panels with the class="panel" are shifted to the right in FireFox, thought in IE6.0 it's shown right below the tabs (aspx .net page).
How to make them look the same in both browsers?

Thanks a lot

WebForm1





.toggle{background:#e6e7e9; width: 100%; height:17px; border-bottom:1px solid #a5b2bd; }
.toggle ul{float:left; margin:0; padding:0; list-style:none; width:550px; }
.toggle li{float:left; font-family:verdana; display:block; padding-bottom:7px; }
.toggle li a{float:left; display:block; text-decoration:none; color:#003DB8 ; }
.toggle li a:visited{color:#003DB8 ; text-decoration:none;}
.toggle li a:hover{text-decoration:underline; }
.toggle li em{float:left; display:block; padding:0 4px; font:10px verdana; margin:8px 0 0 0; font-style:normal; color:#003DB8 ; border-right:1px solid #666; cursor:pointer; }
.toggle li.on{background:url(images/ptr.gif) bottom center no-repeat; }
.toggle li.on a{color:#fff; background:#a5b1bd url(images/tab_left.gif) no-repeat; padding-left:3px; text-decoration:none; }
.toggle li.on a:visited{color:#fff; text-decoration:none;}
.toggle li.on a:hover{text-decoration:none; }
.toggle li.on em{background:#a5b1bd url(images/tab_right.gif) no-repeat top right; margin:0; padding:8px 7px 5px 4px; border:none; font-weight:bold; color:#fff; }
a.tab { border-collapse: collapse; border-style: solid solid none solid; border-color: black; border-width: 1px 1px 0px 1px; background-color: silver; padding: 2px 0.5em 0px 0.5em; margin-top: 4px; font-family: arial; text-decoration: none; }
a.tab:hover { border-color: black; background-color: white; }
.panel { border: solid 1px LightSteelBlue; background-color: white; padding: 2px; height: 250px; width:100%; overflow: auto;}

var panels = new Array('panel1', 'panel2');
var lis = new Array('li1', 'li2');
var selectedTab = null;
function showPanel(tab, name, li)
{
selectedTab = tab;
for(j = 0; j < lis.length; j++)
{
document.getElementById(lis[j]).className = (li == lis[j]) ? 'on':'';
}
for(i = 0; i < panels.length; i++)
{
document.getElementById(panels[i]).style.display = (name == panels[i]) ? 'block':'none';
}
return false;
}