Get script to wait for file dialogue to return
<p>I have a web page where I want to prompt the user for a file to upload, but I don't want to display the <code>&lt;input type="file"/&gt;</code> element.</p>

<p>I have a button that triggers the file dialogue to display, but the code doesn't wait for the dialogue to return.</p>

<p>Is there an event I can hook into that is raised when the file dialogue returns? Is there some other thing I've not thought of?</p>

<p>This is what I have at the moment, it uses an alert to block the code. I want something less hacky.</p>

<pre><code>function importValues(e)
{
    var f = document.getElementById('file');
    f.click();
    alert('loading'); //hack to make the code wait for the user to choose a file before making the ajax call
    var formdata = new FormData(jQuery('#frmImport')[0]);
    jQuery.ajax({
        url: 'importFile',
        type: 'POST',
        data: formdata,
        chache: false,
        contentType: false,
        processData: false,
    });
}
</code></pre>
