If Else Statements in jQuery - *issues*

If Else Statements in jQuery - *issues*

Ok so I am attempting to make an image fader, it has two arrows that appear when you mouse over the right or left had side parts of the image. 

When you click the right arrow, I want the image to fade into the next one, so I wrote up this code:

  2.   $('#rightclick').click(
  3.   function(){
  4.     if('#linkone'.opacity="1") {
  5.   $('#linktwo').animate({"opacity": "1"}, (500));
  6.   $('#linkone').animate({"opacity": "0"}, (250));
  7.   } else if('#linktwo'.opacity="1"){
  8.       $('#linkthree').animate({"opacity": "1"}, (500));
  9.   $('#linktwo').animate({"opacity": "0"}, (250));
  10.   } else if('#linkthree'.opacity="1"){
  11.   $('#linkfour').animate({"opacity": "1"}, (500));
  12.   $('#linkthree').animate({"opacity": "0"}, (250));
  13.   } else if('#linkfour'.opacity="1"){
  14.   $('#linkone').animate({"opacity": "1"}, (500));
  15.   $('#linkfour').animate({"opacity": "0"}, (250));
  16.   }
  17.   });
It works for the first slide, but none after that. Has anyone ever had this issue and solved it or does anyone have any ideas on how to do so?

(Progress can be viewed here: http://benjaminpotter.org/Simak/