[css] Position a div container on the right side

I want to develop some kind of utility bar. I can position each element in this bar side by side using float:left;

But I want the second element to be positioned at the very right of the bar. This is hard for me because the width of the bar is not static.

Have a look at my demo: http://jsfiddle.net/x5vyC/2/

It should look like this:

Any idea how to achieve this using css?

if you don't want to use float

<div style="text-align:right; margin:0px auto 0px auto;">
<p> Hello </p>
</div>
  <div style="">
<p> Hello </p>
</div>

This works for me.

<div style="position: relative;width:100%;">
    <div style="position:absolute;left:0px;background-color:red;width:25%;height:100px;">
      This will be on the left
    </div>

    <div style="position:absolute;right:0px;background-color:blue;width:25%;height:100px;">
      This will be on the right
    </div>
</div>

• Use float: right to.. float the second column to the.. right.
• Use overflow: hidden to clear the floats so that the background color I just put in will be visible.

Live Demo

#wrapper{
    background:#000;
    overflow: hidden
}
#c1 {
   float:left;
   background:red;
}
#c2 {
    background:green;
    float: right
}

Just wanna update this for beginners now you should definitly use flexbox to do that, it's more appropriate and work for responsive try this : http://jsfiddle.net/x5vyC/3957/

#wrapper{
  display:flex;
  justify-content:space-between;
  background:red;
}


#c1{
   background:blue;
}


#c2{
    background:green;
}

<div id="wrapper">
    <div id="c1">con1</div>
    <div id="c2">con2</div>
</div>?