UI Div alignments in CSS Bootstrap and HTML

I have two divs in my UI . One div contains a label . And the other one contains a file selector . I want them to be side by side.

But now they are stacked vertically .

How can I align them horizontally with a little space between them ?

    <div>
        <div>
            <label>Upload File</label>
        </div>
        <div class="ui-select">
            <input type="file" name="files" ng-files="getTheFiles($files)" />
        </div>
    </div>
    <div style="clear:both;"></div>
    <br/>
    <div style="height:3px; background-color:#cccccc; width:100%; margin-top:5px;"></div>
    <div style="padding-top:10px;">
        <input type="submit" class="btn btn-default" style="width:100px;" value="Upload" />

    </div>