Error: Unable to get property 'length' of undefined or null reference

[Blueie]

Hello

 

I am getting the above JavaScript error with fading images in an ASP.NET project.

 

I do not know what causes the error or how to correct it. There are no images on the Web page at the moment, only a link to the JavaScript file that contains the error below:

 

 

 

function gallery() {  //if no images have the show class, grab the first image  var current = ($('ul.slideshow li.show')?  $('ul.slideshow li.show') : $('#ul.slideshow li:first'));  // trying to avoid speed issue  if(current.queue('fx').length == 0) {     // get the next image, if it reached the end of the slideshow, rotate it back to the first image    var next = ((current.next().length) ? ((current.next().attr('id') == 'slideshow-caption')? $('ul.slideshow li:first') :current.next()) : $('ul.slideshow li:first'));         // get the next image caption    var desc = next.find('img').attr('alt');      // set the fade in effect for the next image, show class has higher z-index    next.css({opacity: 0.0}).addClass('show').animate({opacity: 1.0}, 1000);       // hide the caption first, and then set and display the caption    $('#slideshow-caption').slideToggle(300, function () {      $('#slideshow-caption p').html(desc);      $('#slideshow-caption').slideToggle(500);    });       // hide the current image    current.animate({opacity: 0.0}, 1000).removeClass('show');  }}

 

Thank you for any advice.

 

Blueie

[Ingolme]

That means that current.queue('fx') is not returning anything. Perhaps because current is not referring to any elements.

[Blueie]

Hello Foxy

 

Thank you for your reply.

 

So once I upload a few photos to be faded. that error may go away?

 

Thanks again.

[Ingolme]

I would test to make sure and not just assume it will work. I would also make sure that the program is prepared for that situation.