// Copies a string to the clipboard. Must be called from within an 
// event handler such as click. May return false if it failed, but
// this is not always possible. Browser support for Chrome 43+, 
// Firefox 42+, Safari 10+, Edge and IE 10+.
// IE: The clipboard feature may be disabled by an administrator. By
// default a prompt is shown the first time the clipboard is 
// used (per session).
function copyToClipboard(text) {
    if (window.clipboardData && window.clipboardData.setData) {
        // IE specific code path to prevent textarea being shown while dialog is visible.
        return clipboardData.setData("Text", text); 

    } else if (document.queryCommandSupported && document.queryCommandSupported("copy")) {
        var textarea = document.createElement("textarea");
        textarea.textContent = text;
        textarea.style.position = "fixed";  // Prevent scrolling to bottom of page in MS Edge.
        document.body.appendChild(textarea);
        textarea.select();
        try {
            return document.execCommand("copy");  // Security exception may be thrown by some browsers.
        } catch (ex) {
            console.warn("Copy to clipboard failed.", ex);
            return false;
        } finally {
            document.body.removeChild(textarea);
        }
    }
}