<!DOCTYPE html>
<html>
<head>
<style>
#main {
    width: 200px;
    height: 150px;
    border: 1px solid #c3c3c3;
    display: -webkit-flex; /* Safari */
    -webkit-flex-flow: row wrap; /* Safari 6.1+ */
    display: flex;
    flex-flow: row wrap;
}


#main div {
    width: 50px;
    height: 50px;
}

</style>
</head>
<body>

<div id="main">
  <div style="background-color:coral;">A</div>
  <div style="background-color:lightblue;">B</div>
  <div style="background-color:khaki;">C</div>
  <div style="background-color:pink;">D</div>
  <div style="background-color:lightgrey;">E</div>
  <div style="background-color:lightgreen;">F</div>
</div>

<p>Click the "Try it" button to set the value of the flexFlow property to "column nowrap".</p>

<button onclick="myFunction()">Try it</button>

<p><b>Note:</b> Internet Explorer 10 and earlier versions earlier versions do not support the flexFlow property.</p>

<p><b>Note:</b> Safari 6.1 (and newer) supports an alternative, the WebkitFlexFlow property.</p>

<script>
function myFunction() {
    document.getElementById("main").style.WebkitFlexFlow = "column nowrap"; // Safari 6.1+
    document.getElementById("main").style.flexFlow = "column nowrap";
}
</script>

</body>
</html>