Hi all, Iam using Extjs 4.1

I want to display an image after a text field. For this i have used the following code.

The image was coming perfectly. But the problem is when i focused on this textfield or when i place the mouse over that image, that image is being disabled.
And also , i want to show a tooltip for this image.
xtype: 'trigger',
fieldLabel: 'Srinivas',
triggerCls: 'trigger',

the css is :
<style type = "text/css" >
.x-form-trigger-wrap .trigger{background-image:url(delete.png);cursor:pointer;background-repeat: no-repeat;}

Can any body help me in solving this issue...