CIao io uso uno script per sapere la risoluzione dell schermo dell' utente, e vorre in base al dato width = screen.width e al dato height = screen.height caricare uno sfondo diverso nella pagina html.
Ma non so come posso fare?
Vi posto qui il codice delal pagina in questione...grazie a choiunque mi possa essere di aiuto:

<HEAD>

<SCRIPT LANGUAGE="JavaScript">


<!-- Activate Cloaking Device





// Used to display the browser name/version if JavaScript1.2 is not supported

var browser=navigator.appName + " " + navigator.appVersion;



// Though set in the JS1.2 code, these variables are declared here to avoid errors in lesser browsers

var width=null;

var height=null;

var right_browser=false;



// Called by Requirements button

function aboutScheme()

{

alert("\nThis example uses screen.height & screen.width to grab the screen resolution.\n\nThese were introduced in JavaScript1.2.");

}



// Called by View Source button - displays text file of source.

function viewSource()

{

alert("\nA text file with source will be loaded to the full window.\n\nUse your browser BACK button to return to the examples.");

top.window.location.href="js-wid3.txt";

}



// Deactivate Cloaking -->


</SCRIPT>





<SCRIPT LANGUAGE="JavaScript1.2">


<!-- Activate Cloaking Device



// Used to indicate that JS1.2 is supported

right_browser=true;



// Grabs screen resolution

width = screen.width;

height = screen.height;



// Deactivate Cloaking -->


</SCRIPT>


</HEAD>

<body background="../../Documenti/illusion-gruop/Senza titolo-1.jpg" bgcolor="#ffffff" text="#000000" link="#0000ff" vlink="#800080" alink="#ff0000" bgproperties="fixed" leftmargin="0" marginwidth="0" topmargin="0" marginheight="0">

<SCRIPT LANGUAGE="JavaScript">

<!-- Activate Cloaking Device



// If browser supports JS1.2

if(right_browser)

{

document.open();

document.write("<CENTER><FONT SIZE='+1'>La risoluzione del tuo video e'
");

document.write(width + " x " + height);

document.write("</FONT></CENTER>");

}



// If browser does not support JS1.2 - display browser name/version & message

else

{

document.open();

document.write("<CENTER>");

document.write("<FONT SIZE='+1'>"+browser+"</FONT>

");

document.write("<FONT SIZE='+1'>does not support JavaScript1.2.</FONT></CENTER>");

}



// Deactivate Cloaking -->

</SCRIPT>

</BODY>