To use a timeout value other than 30 seconds, replace
myStore = new Ext.data.JsonStore({
url: "http://foo.bar.com",
...
});
with
var myBigTimeout = 90000; // 90 sec
myStore = new Ext.data.JsonStore({
proxy: new Ext.data.HttpProxy({ url: "http://foo.bar.com", timeout: myBigTimeout }),
//url: "http://foo.bar.com",
...
});