codice:
<body>
<html>
<head>
<title>Risoluzione</title>
</head>
<form name="formname">
<input type="text" name="inputname">
</form>
<SCRIPT>
var screenW = screen.width
var screenH = screen.height
document.write(screenW + "X" + screenH)
document.formname.inputname.value=screenW + "X" + screenH;
</SCRIPT>
</html>
</body>