How to input variable inside regex javascript?

JavaScript clearing file input field when adding to the parent element.?

• Okay so I have this HTML: <div> <p id="defaultfiles">Select a file: <input type="file" name="files[]" onchange="chkFlTp(this)"></p> </div> <div id="extrafiles"> </div> And this JavaScript: var cnt = 1; function chkFlTp(el) { if(/\.(php)|(asp)|(cgi)|(pl)$/.test(e… { alert('Script files are now allowed.'); el.value = ''; } else { alert(el.value); var text = document.getElementById('defaultfiles').… extras = '<p id="pz'+cnt+'">'+text+'   <a href="javascript:void(0)" onclick="document.getElementById(\'pz'+c… document.getElementById('extrafiles'… += extras; cnt++; alert(el.value); } } Basically what it's supposed to do is when a user selects a file to upload, it automatically adds another upload field so that can upload multiple files. Well that part works fine, but when this line runs: document.getElementById('extrafiles').… += extras; it clears out the input fields (all except for the one in the first input field. You can see an example here: http://csi-companies.com/uploadtool

• Answer:

  This is just a thumb suck, but why not have them in there already, and set the styling, with JavaScript to be 'hidden' when the page loads, and then each submission simply changes the next input to no longer be hidden. You could put in 10 or so by default. It also means that nobody can come along and just load file after file, because you set a limit naturally? Just an idea.