JavaScript Window
Set the maxWidth property of the jqxWindow. Author: http://jqwidgets.com
by jqwidgets
HTML
<link rel="stylesheet" href="https://jqwidgets.com/public/jqwidgets/styles/jqx.base.css">
<script src="https://jqwidgets.com/public/jqwidgets/jqx-all.js"></script>
<link rel="stylesheet" href="https://jqwidgets.com/public/jqwidgets/styles/jqx.energyblue.css">
<div id='jqxwindow'>
<div>Header</div>
<div>Content</div>
</div>
JavaScript
$("#jqxwindow").jqxWindow({
height: 100,
theme: 'energyblue',
maxWidth: 300
});