1. Put this directly after including ext-all.js:
2. Use:Code:Ext.override(Ext.form.Field, { setFieldLabel : function(text) { this.el.up('.x-form-item', 10, true).child('.x-form-item-label').update(text); } });
Code:Ext.getCmp('id-of-your-text-field').setFieldLabel('other label');