<div>s wont go inline - html

Question

I am offically stumped. There is obvioulsy an easy solution for this, but maybe I just can't see it.
Basically I have a content div with 2 main divs—leftSide and rightside—which I want to display inline. Each side contains other divs. No matter what I try the rightSide div always resorts to displaying under the leftSide div.
HTML
<div id="leftSide">
<h6>MERCHANDISE</h6><img src="images/merch.gif" height="220" width="330" border="0" alt="Organ Thieves - Merch Slideshow"/>
<div id="twitter">
<div class=hr></div>
<h6>FOLLOW US</h6>
<script charset="utf-8" src="http://widgets.twimg.com/j/2/widget.js"></script>
<script>
new TWTR.Widget({
version: 2,
type: 'profile',
rpp: 4,
interval: 30000,
width: 330,
height: 250,
theme: {
shell: {
background: '#525252',
color: '#ffffff'
},
tweets: {
background: '#000000',
color: '#ffffff',
links: '#b51d1d'
}
},
features: {
scrollbar: false,
loop: false,
live: false,
behavior: 'all'
}
}).render().setUser('OrganThieves').start();
</script>
</div><!--end of twitter-->
</div><!--endof leftside-->
<div id="rightSide">
<div id="gigs">
<script type="text/javascript">
var bcGigWidgetWidth=500;
var bcGigWidgetMaxHeight=500;
var bcGigWidgetBackgroundColor="333333";
var bcGigWidgetTextColor="ffffff";
var bcGigWidgetLinkColor="eaeaea";
var bcGigWidgetLineColor="7d7058";
</script>
<script type="text/javascript" src="http://organthieves.bandcentral.com/javascripts/giglistings.js"></script>
<script type="text/javascript" src="http://organthieves.bandcentral.com/gigs/export.js"></script>
</div><!--end gigs-->
</div><!--end of rightSide-->
</div><!--end content-->
CSS
#content{
position: relative;
width: 900px;
}
#leftSide{
width: 330px;
position: relative;
}
#twitter{
position: relative;
width:330px;
}
#rightSide{
position: relative;
width: 570px;
background-color: #339;
height:400px;
display: inline;
}
#gigs{
float: right;
width: 500px;
position: relative;
}

Answer 1

#leftSide and #rightSide need float:left; Also, please make sure their parent element is wide enough for both of them.

Answer 2

check it your code here, float left and right can be used to arrange div horizontally.
http://jsfiddle.net/SfHrb/