Copying to clipboard textbox value using jQuery/JavaScript

I have a textbox & button which looks like this:

     <div class="col-xs-11" style="padding:20px 0 ">
     <input type="text" class="form-control txtKeywords" id="txtKeyw" style="margin-bottom:10px; height:45px;" maxlength="80" placeholder="Click on keywords to combine your title">
   <button type="submit" class="btn btn-space btn-success btn-shade4 btn-lg copyToClipboard">
    <i class="icon icon-left s7-mouse"></i> Copy to Clipboard
     /button>

And when the user clicks the button copy to clipboard, I'd like to copy the contents of the textbox into the clipboard like this:

$(document).on("click", ".copyToClipboard", function () {
    copyToClipboard("txtKeyw");
    successMessage();
});

Where the definition of the copyToClipboard function is:

 function copyToClipboard(element) {
            var $temp = $("<input>");
            $("body").append($temp);
            $temp.val($(element).text()).select();
            document.execCommand("copy");
            $temp.remove();
        }

But when I do this, nothing happens -- no values are copied to clipboard from the textbox... What am I doing wrong here?

MORE INFORMATION:

• This happens in both Chrome 59 64-bit and Firefox 54 32-bit.
• successMessage() is called and displayed in the browser.
• Adding # in front of the element's ID does not resolve the issue.