If Then Statement not working within a success function.

If Then Statement not working within a success function.

Hey All,
 
Just wondering if someone could tell me why my page is not redirecting within the if then statement, here is the code.
 
function addComplaint()
  {
   var datastr = $("#h3sForm").serialize();
   
   $.ajax({
       type: "POST",url: "http://oscscar02/functions/addComplaint.php", dataType: "html",
       data: datastr,
          success: function(html)
           {
            top.alert('Complaint Form Added');
            $('input[name=subBut]').attr('disabled', 'disabled');
            if($("#warranty").is(':checked'))
            {              
             top.location.href = 'http://oscscar02/index.php';
            }
           },
          error: function(XMLHttpRequest, textStatus, errorThrown)
            {
              alert("JQuery ajax error: " + textStatus);
            }
         });
   }




















 
I have tried this without the if then statement and it works fine. I am not sure why my if then statement will not work within success function, am I doing something wrong?