(function($){
$.fn.displayChange = function(fn){
$this = $(this);
var state = {};
state.old = $this.css('display');
var intervalID = setInterval(function(){
if( $this.css('display') != state.old ){
state.change = $this.css('display');
fn(state);
state.old = $this.css('display');
}
}, 100);
}
$(function(){
var tag = $('#content');
tag.displayChange(function(obj){
console.log(obj);
});
})
})(jQuery);