jQuery find element with class name and attribute value

Question

Haven't come up with much as far as documentation goes. How do I find an element with a particular class name that also has a specified attribute value.?

function go_to_page(page){
    $('.page_link[longdesc=page]').addClass('.active_page'); 
}

I got the example from here . Tried testing it myself and it didn't seem to work.

Answer 1

function go_to_page(page){

    $('.page_link[longdesc=' + page + ']').addClass('active_page'); 

}

Answer 2

You have some errors in your syntax, try:

 function go_to_page(page){

     $('.page_link[longdesc='+page+']').addClass('active_page'); 
 }

classes normally don't start with a dot (only in the selector not the name)