Hello Every One,
i am trying to write an application with Ext Js 4.2, but when i was running the application i got the error as follow.

org.mozilla.mod.javascript.EcmaError: ReferenceError: "Ext" is not defined.

the code i wrote as

Ext.create('Ext.Button', {
text: 'Click Me',
enableToggle: true

Can any one please hep to get out from this issue....