copy text to clipbord

copy.js

function copyText(){
    var code = document.querySelector('pre').innerText;
    var select = document.querySelector('#clipboard');
    select.value = code;
    select.select();

    try {
      document.execCommand('copy');
      alert('Text copied to clipboard!');
    } catch (err) {
        window.prompt("To copy the text to clipboard: Ctrl+C, Enter", code);
    }
}