去掉ios弹出框alert和confirm网址问题

<script>
window.alert = function(name){
        var iframe = document.createElement("IFRAME");
        iframe.style.display="none";
        iframe.setAttribute("src", 'data:text/plain,');
        document.documentElement.appendChild(iframe);
        window.frames[0].window.alert(name);
        iframe.parentNode.removeChild(iframe);
    };
window.confirm = function (message) {
            var iframe = document.createElement("IFRAME");
            iframe.style.display = "none";
            iframe.setAttribute("src", 'data:text/plain,');
            document.documentElement.appendChild(iframe);
            var alertFrame = window.frames[0];
            var result = alertFrame.window.confirm(message);
            iframe.parentNode.removeChild(iframe);
            return result;
    };
//alert('abc');
//confirm('are you sure?');
</script>