Simple question about panel opacity 0.4 background

[ginzsa]

I am trying to set a panel with semi transparent background, what do I have to do for the children of the component to NOT inherit the style? thanks in advance...


{
xtype: 'panel',
region: 'center',
layout: 'hbox',
bodyStyle: {background :'#cccccc', opacity: '0.4',margin: '10 10 10 10'},

items:[
{
xtype: 'textfield',
text: 'any text',
bodyStyle: { opacity: '1.0'}


},{
xtype: 'button',
text: 'any button'
}
]
}