How come the CSS in my JavaScript won't work?

Question

I am trying to make a box pop up when i click on it. Here is the HTML for the boxes:

<div id="content_1">
    <p>Hello</p>
    <p>Please push the button</p>
    <p><input type="button" id="go_button" value="Go"/> </p>
</div>
<div id="box">
    <p>hello</p>
</div>

Here is the JavaScript and CSS:

$(document).ready(function() {
    $("#content_2").on("click",function(){
    .css("z-index",3);
    }
}

Here is the styling just in case it's needed:

#go_button {

}
#content_1 {
margin:20px auto;
position:fixed;
width:1000px;
text-align:center;
border:1px solid #d0d0d0;
box-shadow:1px 1px 5px #aaa;
border-radius:15px;
background:#99FF99;
z-index:3;
}
#box {
position:fixed;
top:100px;
left:300px;
z-index:1;
width:600px;
height:300px;
background:green;
}
body {
background:#f7f7f7;
}

Answer 1

You cannot call a method chain without anything to start it. We don't see an element with the id content_2 in your markup. Perhaps you mean to apply this to #content_1 .

$(document).ready(function() {
    $("#content_2").on("click",function(){
        // Apply to this
        $(this).css("z-index",3);
    });
});

If the CSS is to be applied to some other element rather than content_2 ( this ), use its selector instead.

$(document).ready(function() {
    $("#content_2").on("click",function(){
        $('#box').css("z-index",3);
    });
});

Note that unless you have specified position: absolute or position: fixed , that z-index won't have any effect.

Answer 2

Try this

$(document).ready(function() {
    $("#content_2").on("click",function(){
    $(this).css("z-index",3);
    }
}

Answer 3

It looks like you aren't applying the css to anything:

$(document).ready(function() {
$("#content_2").on("click",function(){
        $('#box').css("z-index",3);
    }
}

Also, #content_2 isn't defined.