[_marisha]

laimas,

function fun1() {
var chbox;
chbox=document.getElementById('sbor');
    if (chbox.checked) {
       var sbor = '1';
          $.ajax({
          url: "summary.php",
          type : "POST",
          data : {sbor:sbor},
         });
    }
    else {
        var message;
       message = '0';
       alert(message);
    }
}

В summary.php echo $_POST['sbor']; пусто