How to make image of the button visible even after it is pressed in sencha

I am using sencha to create an application. In this i am using button which for which i have defined the icons.

ex:

• Sencha

  { xtype:'button', height:30, width:30, cls:'btn' }

• CSS

  .btn { background:"../../resources/img/hosrse.png"; }

  开发者_C百科

But when i am clicking on the button the image is disappearing. What to do to keep the image appear even after pressing the button.

---

You need to overload the .x-button-pressed rule, i.e.

.btn.x-button.x-button-plain,
.btn.x-button.x-button-plain.x-button-pressed {
    background:"../../resources/img/hosrse.png";
}