I am using Ext JS for my project. I got a sample javascript code from the web that I would like to try out. I couldn't find a right way to invoke the sample code form Ext JS based code that I have.
Is there an example?
Not sure what you mean by "invoke". ExtJS is just javascript and you can call other javascript from it.
Here is a JQuery widget running inside an ExtJS container:
http://extjs-tutorials.blogspot.ca/2012/08/extjs-jquery-together-same.html