Try this code to change the icon class on a panel.
$('#p').panel({
iconCls: '...'
});
I have tried this, I have many "<a>" links click to refresh panel, it only work once, if you do it again : Uncaught TypeError: Cannot read property 'panel' of undefined
$('.esys-sysmenu').find('a').click(function (e) {
e.preventDefault();
// $('#esys-item').panel({
// title:$(this).text(),
// iconCls:$(this).linkbutton('options').iconCls
// });
// if use code up then Uncaught TypeError: Cannot read property 'panel' of undefined
$('#esys-item').panel('refresh', this.href);
$('#esys-item').panel('setTitle',$(this).text());
//$('#esys-item').panel('options').iconCls = $(this).linkbutton('options').iconCls; //this not work
return false;
})