Very long response while loading JSONP

[indapublic]

I try to load store by using JSONP

var store = Ext.data.StoreManager.lookup('need_store');

store.setProxy({
	type: 'jsonp',
	url: 'myurl'
});

store.load();

JSON output like:

Mycallback([['name1', 'id1', 'price1'], ['name2', 'id2', 'price2']]

I declare Mycallback function in index.html

<script type="text/javascript">
	    ...	    
	    function Mycallback(data) {
	    	g_App.getController('MyController').Load(data);
    	}
    </script>

MyController.Load

{
return;
}

So I don't add items into store. But indicator "Loading..." shows about 5 seconds! Chrome debug says, GET url takes 65 ms. What's wrong?

[mitchellsimoens]

The callback method name that should be returned in your response is automatically sent as a param in the request. You don't need to do anything client side, just use what is sent in your response.

[indapublic]

I have invariable function name in JSON, and I must to declare my function in such way