function setDataToclipboard()
{

var str=document.getElementById("populatedString").value;

if (window.clipboardData && clipboardData.setData) {
    clipboardData.setData("Text", str);
    alert("Copied!");
}
}

<button id="my-button" data-clipboard-text="Copy me!">Copy to Clipboard</button>
<script>
    var clip = new ZeroClipboard(document.getElementById('my-button'));
</script>

clipboard = e.originalEvent.clipboardData;
clipboard.setData('text/plain', plainData);
clipboard.setData('text/html', htmlData);

<input id="e" type="hidden" value="my text to copy to clipboard">

<input id="e" type="text" style="display:none;" value="my text to copy to clipboard">

<input id="e" type="text" style="position: absolute; top: -30;" value="my text">