How to delete cache file in webView

app.js

/*When we load any website site in webView it generate some cache file also in the app cacheDirectory we
can delete this easily, here is the sample code*/

var win = Ti.UI.createWindow({
	layout : 'vertical',
	exitOnClose : true
});

var delBtn = Ti.UI.createButton({
	top : 10,
	left : 0,
	right : 0,
	height : '50',
	title : '2) Delete Cache'
});
delBtn.addEventListener('click', function(e) {
	var webViewCacheDir = Ti.Filesystem.getFile(Ti.Filesystem.applicationCacheDirectory, "webviewCache");

	Ti.API.info('CACHE DIR');
	Ti.API.info("cacheDiroctory=" + Ti.Filesystem.applicationCacheDirectory);
	Ti.API.info('CONTENTS');
	Ti.API.info(webViewCacheDir.getDirectoryListing());

	Ti.API.info('Array length before: ' + webViewCacheDir.getDirectoryListing().length);

	webViewCacheDir.deleteDirectory(true);

	Ti.API.info('Array length after: ' + webViewCacheDir.getDirectoryListing().length);
});
var reloadBtn = Ti.UI.createButton({
	top : 10,
	left : 0,
	right : 0,
	height : '50',
	title : '1) Reload'
});
reloadBtn.addEventListener('click', function(e) {
	webview.reload();
});

var deallocateBtn = Ti.UI.createButton({
	top : 10,
	left : 0,
	right : 0,
	height : '50',
	title : '3) Deallocate'
});
deallocateBtn.addEventListener('click', function(e) {
	Ti.API.info('Deallocating WebView ');
	win.close();
	win.remove(webview);
	webview = null;
	Ti.API.info('WebView: ' + webview);
});
var webview = Ti.UI.createWebView({
	top : 0,
	height : '200dp',
	left : 0,
	right : 0,
	url : 'http://www.appcelerator.com/'
});

win.add(webview);

win.add(reloadBtn);
win.add(delBtn);
win.add(deallocateBtn);
win.open();