checkbox is disabled but changes the value on checkbox click

I have a checkbox in my form. I have made it disable by setting its property like

    var id = document.getElementById("FeeId").value;
    if (id > 0) {
        $("#IsRural").attr('disabled', true);
    }

The problem is when I click on this disabled checkbox it changes the value in db. But it appears to be disabled in form. Need help.