function addLink() {
//Get the selected text and append the extra info
var selection = window.getSelection(),
uzunluk = selection.toString().length,
pagelink = '

Read more at: ' + document.location.href,
copytext = selection + pagelink,
newdiv = document.createElement('div');

//hide the newly created container
newdiv.style.position = 'absolute';
newdiv.style.left = '-99999px';

//insert the container, fill it with the extended text, and define the new selection
if (uzunluk >= 200) document.body.appendChild(newdiv);
newdiv.innerHTML = copytext;
selection.selectAllChildren(newdiv);

window.setTimeout(function () {
document.body.removeChild(newdiv);
}, 100);
}

document.addEventListener('copy', addLink);