Buon Giorno a tutti,

Sono appena iscritto oggi e quindi sono nuovo con voi

comunque vorrei risolvere il problema che nel mio sito forum il menù a tendina allineato a sinistra, ma io voglio modificare per diventare in centrato come si fa? mi potresti spiegarmi?

ecco il css

codice:
/* Styles for the standard dropdown menus.
------------------------------------------------------- */
#main_menu
{
   background: #000000;
   float: left;
   margin: 0;
   width: 100%;
   padding:7px 2px 7px 0px;
}

.dropmenu, .dropmenu ul
{
   list-style: none;
   line-height: 1em;
   padding: 0;
   margin: 0;
   font-size: 12px;
}
.dropmenu
{
   padding: 0 0.5em;
}
.dropmenu a
{
   display: block;
   color: #FF0000;
   text-decoration: none;
}
.dropmenu a span
{
   display: block;
   padding: 0 0 0 5px;
   font-size: 0.9em;
}
/* the background's first level only */
.dropmenu li a.firstlevel
{
   margin-right: 5px;
}
.dropmenu li a.firstlevel span.firstlevel
{
   display: block;
   position: relative;
   left: -5px;
   padding-left: 5px;
   height: 22px;
   line-height: 19px;
   white-space: pre;
}
.dropmenu li
{
   float: left;
   padding: 0;
   margin: 0;
   position: relative;
}
.dropmenu li ul
{
   z-index: 90;
   display: none;
   position: absolute;
   width: 19.2em;
   font-weight: normal;
   border-bottom: 1px solid #999;
   background: url(../images/theme/menu_gfx.png) 0 -130px no-repeat;
   padding: 7px 0 0 0;
}
.dropmenu li li
{
   width: 19em;
   margin: 0;
   border-left: 1px solid #999;
   border-right: 1px solid #999;
}
.dropmenu li li a span
{
   display: block;
   padding: 2px;
}
.dropmenu li ul ul
{
   margin: -1.8em 0 0 13em;
}

/* the active button */
.dropmenu li a.active
{
   background: url(../images/theme/menu_gfx.pn) no-repeat 100% 0;
   color: #fff;
   font-weight: bold;
}
.dropmenu li a.active span.firstlevel
{
   background: url(../images/theme/menu_gfx.pn) no-repeat 0 0;
}
/* the hover effects */
.dropmenu li a.firstlevel:hover, .dropmenu li:hover a.firstlevel
{
   background: url(../images/theme/menu_gfx.pn) no-repeat 100% -30px;
   color: #fff;
   cursor: pointer;
   text-decoration: none;
}
.dropmenu li a.firstlevel:hover span.firstlevel, .dropmenu li:hover a.firstlevel span.firstlevel
{
   background: url(../images/theme/menu_gfx.pn) no-repeat 0 -30px;
}
/* the hover effects on level2 and 3 */
.dropmenu li li a:hover, .dropmenu li li:hover>a
{
   background: #d4dbe4;
   color: #000;
   text-decoration: none;
}
.dropmenu li:hover ul ul, .dropmenu li:hover ul ul ul
{
   top: -999em;
}
.dropmenu li li:hover ul
{
   top: auto;
}
.dropmenu li:hover ul
{
   display: block;
}
.dropmenu li li.additional_items
{
   background-color: #AED504;
}

/* The dropdown menu toggle image */
#menu_toggle
{
   float: right;
   margin-right: 10px;
   padding-top: 3px;
}
#menu_toggle span
{
   position: relative;
   right: 5000px;
}
Ti aspetto la vostra risposta d'aiuto.
Distinti Saluti
Baldassarre Michele