Il codice finora funziona benissimo, ma solo per il campo e-mail.

Eccolo:

codice:
<html>
<head>
 
<title>Studio Dentistico Polispecialistico - Dr. Pier Luigi Floris</title>
 
<META HTTP-EQUIV="imagetoolbar" CONTENT="no">
<META HTTP-EQUIV="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" type="text/JavaScript">
<!--
function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_validateForm() { //v4.0
  var i,p,q,nm,test,num,min,max,errors='',args=MM_validateForm.arguments;
  for (i=0; i<(args.length-2); i+=3) { test=args[i+2]; val=MM_findObj(args[i]);
    if (val) { nm=val.name; if ((val=val.value)!="") {
      if (test.indexOf('isEmail')!=-1) { p=val.indexOf('@');
        if (p<1 || p==(val.length-1)) errors+='- '+nm+' deve essere valida.\n';
      } else if (test!='R') { num = parseFloat(val);
        if (isNaN(val)) errors+='- '+nm+' must contain a number.\n';
        if (test.indexOf('inRange') != -1) { p=test.indexOf(':');
          min=test.substring(8,p); max=test.substring(p+1);
          if (num<min || max<num) errors+='- '+nm+' must contain a number between '+min+' and '+max+'.\n';
    } } } else if (test.charAt(0) == 'R') errors += '- '+nm+' necessaria.\n'; }
  } if (errors) alert('Inserire email valida:\n'+errors);
  document.MM_returnValue = (errors == '');
}
//-->
</script>

 
<style type="text/css">
<!--
-->
</style>
<link href="stylealtrepagtr2.css" rel="stylesheet" type="text/css">
</head>
<body bgcolor="#33CCCC" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<table width="800" border="0" align="center" cellpadding="0" cellspacing="0">
  
  <tr> 
    <td>[img]spacer.gif[/img]</td>
    <td>[img]spacer.gif[/img]</td>
    <td>[img]spacer.gif[/img]</td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td rowspan="5">[img]imges/layout3_r1_c1.gif[/img]</td>
    <td colspan="2" bgcolor="#33CCCC"><div align="center">  
        

 [img]titleflo.jpg[/img]</p>
        </div></td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td colspan="2" bgcolor="#33CCCC"><div align="center">Sassari, via Zanfarino 
        40 - tel. 079 274322</div></td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td rowspan="2">[img]imges/layout3_r3_c2.gif[/img]</td>
    <td>[img]imges/layout3_r3_c3.gif[/img]</td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td rowspan="2" valign="top" bgcolor="#CCFFCC"><div align="center"> 
        <script src="xaramenu.js"></script>
        <script webstyle3 src="barra.js"></script>
      </div></td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td bgcolor="#CCFFCC"></td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td valign="top" bgcolor="#CCFFCC"> 
      <div align="center">
        <table width="98%" border="1" cellspacing="5" ID="tableSpot">
          <tr> 
            <td id="cellaSpot" valign="top" background="specch4.gif"> 
              <p ID="paragSpot" align="center"></p>
              </td>
          </tr>
        </table>
        
      </div></td>
    <td colspan="2" valign="top" bgcolor="#CCFFCC"> <div align="justify">
        <table width="90%" border="0" align="center">
          <tr> 
            <td></td>
            <td width="99%" valign="top"> 
              <div align="justify"> 
                <h1 align="center">Compila questo modulo per chiederci

                  informazioni e/o suggerimenti.</h1>
                <form action="formcdosys.asp" method="post" name="form1" id="form1Info" onSubmit="MM_validateForm('e-mail','','RisEmail');return document.MM_returnValue">
                  <table width="80%" border="0" align="center" cellspacing="5">
                    <tr> 
                      <td nowrap>Nome</td>
                      <td><input name="Nome" type="text" id="Nome" size="50" maxlength="50" /></td>
                    </tr>
                    <tr> 
                      <td nowrap>Cognome</td>
                      <td><input name="Cognome" type="text" id="Cognome" size="50" maxlength="50" /></td>
                    </tr>
                    <tr> 
                      <td nowrap>Indirizzo</td>
                      <td><input name="Indirizzo" type="text" id="Indirizzo" size="50" maxlength="300" /></td>
                    </tr>
                    <tr> 
                      <td nowrap>Telefono</td>
                      <td><input name="Telefono" type="text" id="Telefono" size="50" maxlength="50" /></td>
                    </tr>
                    <tr> 
                      <td nowrap>Cellulare</td>
                      <td><input name="Cellulare" type="text" id="Cellulare" size="50" maxlength="50"></td>
                    </tr>
                    <tr> 
                      <td nowrap>E-mail *</td>
                      <td><input name="E-mail" type="text" id="E-mail" size="50" maxlength="50" /></td>
                    </tr>
                    <tr> 
                      <td nowrap>Cosa desideri?</td>
                      <td><input name="Informazioni" type="checkbox" id="Informazioni" value="Si">
                        Informazioni</td>
                    </tr>
                    <tr> 
                      <td nowrap></td>
                      <td><input name="Preventivo" type="checkbox" id="Preventivo" value="Si">
                        Suggerimenti</td>
                    </tr>
                    <tr> 
                      <td>Altre richieste o commenti</td>
                      <td><textarea name="Commenti" cols="50" rows="5" id="Commenti"></textarea></td>
                    </tr>
                    <tr> 
                      <td colspan="2" nowrap><h2 align="center">N.B.: I campi 
                          contrassegnati con l'asterisco sono obbligatori</h2></td>
                    </tr>
                    <tr> 
                      <td nowrap></td>
                      <td></td>
                    </tr>
                    <tr> 
                      <td nowrap></td>
                      <td><input type="submit" name="Submit" value="Spedisci il modulo"> 
                        <input name="Cancel" type="reset" id="Cancel" value="Annulla"></td>
                    </tr>
                  </table>
                </form>
              </div>
              </td>
            <td></td>
          </tr>
        </table>
      </div>
      <p align="justify">

        </p></td>
    <td valign="top">[img]spacer.gif[/img]</td>
  </tr>
  <tr> 
    <td colspan="3" bgcolor="#CCFFCC">
<div align="center"></div></td>
    <td>[img]spacer.gif[/img]</td>
  </tr>
</table>
<map name="layout3_r1_c1Map">
  <area shape="circle" coords="84,83,74" href="http://www.florisdental.it">
  <area shape="circle" coords="71,101,1" href="#">
</map>
</body>
</html>