far scorrere il corpo pagina

qualcuno mi dice come vanno messe le impostazioni per fare sì che scorra solamente il corpo della pagina ma lo sfondo rimanga sempre tale?

un po' come su questo sito dove, se si va in giù con il mouse, lo sfondo resta fermo.

nel css :

Codice:

---

background-attachment:fixed;

---

Codice:

---

body {
font-size: 12px;
font-family: Arial, sans-serif;
line-height: 1.6;
color: #393939;
background-color: #eeeeee;
background-image: url(/alterpages/sfondofinale.jpg#gallery);


}

#header {

background-color: #286bc2;

background-image: url("/alterpages/testatafinale.jpg#gallery");
min-height: 180px;

background-repeat: no-repeat;

}

#wrap {
background-color: #ffffff;
background-image: url('http://cuorebiancoblu.altervista.org/alterpages/sfondocorpopagina.jpg#gallery');
background-repeat: repeat;
background-position: top center;
}

#content {




}

#sidebar {
color: #ffffff;
background-color: #6baae4;
background-image: url('http://cuorebiancoblu.altervista.org/alterpages/sfondosidebar.jpg#gallery');
background-repeat: repeat-y;
background-position: top center;
}

h1 {
color: #000000;
font-size: 36px;
font-family: Arial, sans-serif;
}

h2 {
color: #212121;
font-size: 20px;
}

a {
color: #0e4fa3;
}

/* --- border --- */
#wrap, #header, #footer, ul.nav > li > a, ul.nav li ul  {
border-color: #2e9afe;
}

/* --- nav sidebar --- */
div#sidebar ul.nav, div#sidebar ul.nav a {
color: #494949;
}
div#sidebar ul.nav a:hover {
color: #286bc2;
}
div#sidebar ul.nav > li > a {

}

/* border custom nav sidebar */
div#sidebar ul.nav > li > a, div#sidebar ul.nav li ul {
border-color: #E0E0E0;
}

/* --- nav header --- */
div#header ul.nav, div#header ul.nav a {
color: #ffffff;
}
div#header ul.nav a:hover {
color: #ffffff;
background-color: #669BCC;
}
div#header ul.nav > li > a,  div#header ul.nav li ul {
background-color: #AB2721;
}
/* border custom nav header */
div#header ul.nav > li > a, div#header ul.nav li ul {
border-color: #ffffff;
}

/* --- #navigation --- */

div #navigation {

}

div#navigation ul.nav, div#navigation ul.nav li, div#navigation ul.nav ul {
background-color: #286bc2;
}

div#navigation ul.nav li a {
color: #ffffff;
}

div#navigation ul.nav li:hover, div#navigation ul.nav li:hover ul li, div#navigation ul.nav ul {
background-color: #0e4fa3;
}

div#navigation ul.nav li:hover a, div#navigation ul.nav ul a {
color: #ffffff;
}

/* --- styles --- */


h1 {font-weight:normal}
h2 {font-weight:bold}

#wrap {
-moz-border-radius: 4px 4px 4px 4px;
border-radius: 4px 4px 4px 4px;
padding:10px 0;
margin: 20px auto
}

#header  {
border-bottom-style: solid;
border-bottom-width: 1px;
padding-top:0;
}

div#header .widget-nav {
padding:0
}

div #header ul.nav {
margin: 0 0 10px 0;
}

div#header .title {
padding:10px
}

div#header ul.nav li ul, div#sidebar ul.nav li ul {
list-style-type:disc; /* static list type */
}

div#footer {
font-size: 90%;
}

div#sidebar ul.nav a, div#sidebar ul.nav li ul {
border-bottom-width: 1px;
border-bottom-style: dashed;
}

/* --- #navigation custom --- */

div#navigation ul.nav ul {
border-bottom-width:2px;
border-bottom-style:solid;
border-color: #0b4084;
}

div#navigation ul.nav li {
border-right-width:1px;
border-right-style:solid;
border-color: #ffffff;
}

div#navigation ul.nav ul li {
border:none;
}

div#navigation {
border-bottom-width:1px;
border-bottom-style:solid;
border-color: #0b4084;
}

---

questo è il mio css. attachment non c'è...

infatti lo devi aggiungere tu!

Codice:

---

body {
font-size: 12px;
font-family: Arial, sans-serif;
line-height: 1.6;
color: #393939;
background-color: #eeeeee;
background-image: url(/alterpages/sfondofinale.jpg#gallery);
background-attachment: fixed;
}

---

Attenzione che se usi Alterpages le modifiche manuali ai file finiranno per essere sovrascritte.