Errori W3C

Line 242, Column 105: required attribute "alt" not specified 
…" width="346" height="99" align="top"/><font face="helvetica" size="+1"><br />…✉ 
The attribute given above is required for an element that you've used, but you have omitted it. For instance, in most HTML and XHTML document types the "type" attribute is required on the "script" element and the "alt" attribute is required for the "img" element. 

Typical values for type are type="text/css" for <style> and type="text/javascript" for <script>.

Line 247, Column 213: required attribute "alt" not specified 
…a altro che complicare.</font><img src="Fondo_Contenitore_centrale.jpg"/><br />✉ 
The attribute given above is required for an element that you've used, but you have omitted it. For instance, in most HTML and XHTML document types the "type" attribute is required on the "script" element and the "alt" attribute is required for the "img" element. 

Typical values for type are type="text/css" for <style> and type="text/javascript" for <script>.

Non capisco dove stanno gli errori

[darkwolf]

L'immagine richiede il testo alternativo (alt).
Cambia quindi:

<img src="Fondo_Contenitore_centrale.jpg"/>

in:

<img src="Fondo_Contenitore_centrale.jpg" alt="" />

(per passare l'errore puoi lasciarlo anche vuoto ma sarebbe meglio indicare un testo alternativo).

Ma perchè sta cosa?

Comunque grazie. :)

[darkwolf]

Chiedilo al W3C > http://www.w3.org/QA/Tips/altAttribute
Figurati

Questi tipi di errori cosa significano:

Byte-Order Mark found in UTF-8 File.

The Unicode Byte-Order Mark (BOM) in UTF-8 encoded files is known to cause problems for some text editors and older browsers. You may want to consider avoiding its use until it is better supported.

document type does not allow element "ul" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
<ul id="menu_a_2livelli">✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").

document type does not allow element "hr" here; assuming missing "li" start-tag
…top: -8px; margin-left: -1495px;" size="0" width="930" noshade="noshade"></hr>

end tag for "li" omitted, but OMITTAG NO was specified
</ul>✉
You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".

Per caso si deve chiudere con />...ma cosi verrebbe fuori </ul />

start tag was here
<hr style=" z-index:35px; margin-top: -8px; margin-left: -1495px;" size="0" wid…

document type does not allow element "hr" here; assuming missing "li" start-tag
…top: -8px; margin-left: -1495px;" size="0" width="930" noshade="noshade"></hr>

document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
…style="margin-left:18px; width:120px;"><a href="Febbraio_cure_alle_piante.html…✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").

[darkwolf]

Se non linki la pagina o il codice interessato sarà difficile aiutarti.

A qualche errore sono riuscito a rimediare.

Comunque questo è la parte del codice: http://astropvt.altervista.org/Test/...testo__2_.html

Quì c'è tutta la pagina: http://astropvt.altervista.org/Test/Home_Giugno.html

[darkwolf]

Allora, la struttura a liste dovrebbe mantenere quest'ordine:

<ul>
 <li>***</li>
</ul>

E un hr li in mezzo non è proprio il caso (al massimo metti un border al li).
Inoltre l'hr non ha bisogno di chiusura </hr> ma del self close: <hr />

Ma così, come ho fatto, non va bene?

<ul>
    <li>
        <ul>
            <li>
            </li>
        </ul>
    </li>
</ul>

E un hr li in mezzo non è proprio il caso (al massimo metti un border al li).

Come dici te, è possibile realizzare questo menù: http://astropvt.altervista.org/BIANCA.jpg il menù sotto il titolo intendo.

Inoltre l'hr non ha bisogno di chiusura </hr> ma del self close: <hr />

Fatto ma sono spuntati un bel po di altri errori:
Ad es:

Line 127, Column 25: document type does not allow element "ul" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
<ul id="menu_a_2livelli">✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").

Line 132, Column 1: start tag was here
<hr style=" z-index:35px; margin-top: -8px; margin-left: -1495px;" size="0" wid…