<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
div {
border: 1px solid red;
}
#left {
float: left;
}
#right {
float: right;
}
#middle {
overflow: hidden
}
</style>
</head>
<body>
<div id="parent">
<div id="left">
test <br>test
</div>
<div id="right">
test <br>test
</div>
<div id="middle">
test <br>test test <br>test test <br>test
</div>
</div>
</body>
</html>