[рони]

Arroyo,

document.oncopy = function () {
    var bodyElement = document.body;
    var selection = getSelection();
    var href = document.location.href;
    var copyright = "кошка "+ href;
    var pos = (''+selection).lastIndexOf("Собака");
    pos == -1 && (pos = (''+selection).length, copyright = " "+href);
    String.prototype.replaceAt=function(index, character) {
        return this.substr(0, index) + character + this.substr(index+6);
    }

    var text = (''+selection).replaceAt(pos, copyright);
    var divElement = document.createElement('div');
    divElement.style.position = 'absolute';
    divElement.style.left = '-99999px';
    divElement.innerHTML = text;
    bodyElement.appendChild(divElement);
    selection.selectAllChildren(divElement);
    setTimeout(function() {
    bodyElement.removeChild(divElement);
    }, 0);
};