How to put X inside textfield to clear text in extjs

I want to implement an X button inside a textfield (x on right side of textfield) to clear entered texts. I have seen many extjs application that has this feature. How do I go about doing that? Any suggestion or comments would be really appreciated... THanks

it looks something like this...

You have to use a Ext.form.field.Trigger. Here is a example for that

Ext.define('Ext.ux.CustomTrigger', {
    extend: 'Ext.form.field.Trigger',
    alias: 'widget.customtrigger',
    initComponent: function () {
        var me = this;

        me.triggerCls = 'x-form-clear-trigger'; // native ExtJS class & icon

        me.callParent(arguments);
    },
    // override onTriggerClick
    onTriggerClick: function() {
        this.setRawValue('');
    }
});

Ext.create('Ext.form.FormPanel', {
    title: 'Form with TriggerField',
    bodyPadding: 5,
    width: 350,
    renderTo: Ext.getBody(),
    items:[{
        xtype: 'customtrigger',
        fieldLabel: 'Sample Trigger',
        emptyText: 'click the trigger'
    }]
});

For ease of testing, here is a JSFiddle