Question: I have NEXT and PREVIOUS buttons on my screen. When the page initially loads I want the Previous button to be hidden and as soon as user clicks the Next button I want Previous button (div tag to be visible). I have a CSS property for Previous button where I am setting the visibility value to False. 
And also an if statement where I check to see if page counter is greater than 1 then change the visibility of navigationButtonTop to true. It is not working..what am I doing wrong !?

```js
$(function() {
  $("#navigationButtonTop").css("visibility", "visible");
});
```

```css
div.navigationButtonTop {
  visibility: hidden;
  height: 100px;
  width: 100px;
  background-color:blue;
}
```

```html
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class="navigationButtonTop"></div>
```

Answer: 
In your JS you use ID ("#" sign before selector's name). But in your CSS you use CLASS (dot sign before selector's name).

Try to use "#" in both cases (or dot accordingly).
Havde you tried $("#navigationButtonTop").show();