webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient() {

            @Override
            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
                Toast.makeText(getApplicationContext(), "Sayfa Yüklenemedi!",
                        Toast.LENGTH_SHORT).show();
                finish();

            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);

        });