if语句在jqueryajax调用中不起作用?

 jQuery.ajax({
                type: "POST",
                url: "/ajax/uiProcessPhoto.php",
                data: "action="+ action,
                success: function(response){            
                    var s_response = response.split("|");
                    var qsize = data.fileCount;     
                    var ptotal = s_response[0];
                    var ltotal = s_response[1];
                    var allowed = s_response[1] - s_response[0];        
                    if (ptotal >= ltotal){
                    alert("Unable to add photos to queue. You have reached the maximum number of photo uploads allowed.");
                    }else if (ptotal + qsize >= ltotal){                    
                    alert("The total photos select will exceed the maximum upload limit. Please upload up to " + allowed + " more photos to continue.");
                    }else if (response == 1){
                    jQuery('#upload').show();
                    };
                    alert(allowed);
                    }   
                });