function checkRiservata(){
    $.post('login.aspx', { utente: $("#utente").val(), password: $("#password").val() }, 
         function(data){
             if (data == 'login'){
                window.location="area_riservata.aspx";
             }else{
                $("#dialog").dialog('open')
             }
         } 
    );
}
$(function(){
        $("#dialog").append("<p id='validateTips'>Inserisci utente e password.</p><span id='errore'>&nbsp;</span><table width='100%'><tr><td>Utente</td><td><input type='text' name='utente' id='utente' class='testo ui-widget-content ui-corner-all' /></td></tr><tr><td>Password</td><td><input type='password' name='password' id='password' value='' class='testo ui-widget-content ui-corner-all' /></td></tr></table>")

        $("#dialog").dialog({
        bgiframe: true,
        autoOpen: false,
        height: 210,
        closeOnEscape: true,
        modal: true,
        buttons: {
	        'Log-in': function() {
		        var bValid = true;
		        //allFields.removeClass('ui-state-error');
		        $("#errore").removeClass("ui-state-error");
                $.post('login.aspx', { utente: $("#utente").val(), password: $("#password").val() }, 
                     function(data){
                         if (data == 'login'){
                            window.location="area_riservata.aspx";
                         }else{
                            $("#errore").addClass("ui-state-error");
                            $("#errore").html(data);
                         }
                     } 
                );
	        },
	        'Esci': function() {
	            $("#utente").val('');
	            $("#password").val('');
	            $("#errore").html('&nbsp;');
		        $("#errore").removeClass("ui-state-error");
		        $(this).dialog('close');
	        }
        },
        close: function() {
	        //allFields.val('').removeClass('ui-state-error');
	            $("#utente").val('');
	            $("#password").val('');
	            $("#errore").html('&nbsp;');
		        $("#errore").removeClass("ui-state-error");
        }
    });

});