webView.setWebViewClient(new myWebClient());
    webView.getSettings().setJavaScriptEnabled(true);
    webView.getSettings().setBuiltInZoomControls(true);
    webView.getSettings().setDisplayZoomControls(false);
    webView.getSettings().setSupportZoom(true);
    webView.loadUrl("file:///android_asset/html/index.html");

public class myWebClient extends WebViewClient
{
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
        progressBar.setVisibility(View.VISIBLE);
    }

    @Override
    public boolean  shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
        super.shouldOverrideUrlLoading(view, request);
        progressBar.setVisibility(View.VISIBLE);
        return true;
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        // TODO Auto-generated method stub
        super.onPageFinished(view, url);
        progressBar.setVisibility(View.INVISIBLE);
    }

    @Override
    public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
        super.onReceivedError(view, request, error);
        webView.loadUrl("file:///android_asset/html/error.html");
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.search, menu);

    MenuItem searchItem = menu.findItem(R.id.action_search);
    SearchView searchView = (SearchView)searchItem.getActionView();
    searchView.setOnQueryTextListener(this);
    searchView.setQueryHint(getString(R.string.search_hint));
    searchItem.setOnActionExpandListener(this);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    return super.onOptionsItemSelected(item);
}

@Override
public boolean onMenuItemActionExpand(MenuItem item) {
    return true;
}

@Override
public boolean onMenuItemActionCollapse(MenuItem item) {
    return true;
}

@Override
public boolean onQueryTextSubmit(String query) {
    buscaString(query);
    return true;
}

@Override
public boolean onQueryTextChange(String newText) {
    return true;
}

public void buscaString(String s){

  webview.loadUrl("javascript:func('" + s + "')");

}

function func(val){
 alert(val);
}