[CLOSED] Disable shadowing on panel tool items

[SymSure]

hi,

How do I disable shadowing effect on the panel tool items. For example I want to be able to disable the shadowing effect on the close button on a panel.

{                     
    title:"testing"                
  closable: true,
                      autoscroll: false,                      
                      monitorResize: true,
                      width: 600,
                      frame: true,
                      height: 320                       
                      tools: [
                                 {
                                      id: 'close'                                      
                                  }  
                            ]
                      
                  };

regards