Mancavano due parentesi graffe dell'else :
codice:
function onsubmitform()
{
if(document.pressed == 'Insert')
{
document.myform.action ="insert.html";
}
else
{
if(document.pressed == 'Update')
{
document.myform.action ="update.html";
}
}
return true;
}
</script>
<form name="myform" onsubmit="return onsubmitform();">
<input type="submit" name="operation" onclick="document.pressed=this.value" value="insert" />
<input type="submit" name="operation" onclick="document.pressed=this.value" value="update" />
</form>