Show load/wait mask, when using DIRECT store with autoSync, how to?

Hi dear sirs/madams,

i am using autoSync feature and i would like to show load/wait mask, for every operation (read, write) and when operation would finish, i would hide load mask.

I know if i run sync() manually, i can do it like this:

Code:

var myMask = new Ext.LoadMask({
    msg    : 'Please wait...'
});

myMask.show();

store.sync({
   callback: function(){
      myMask.hide();
   }
});

Can someone suggest me where to put code to capture event before sync and when sync is finished?

best regards,

Andrej