I managed to solve it, in case someone need it:
function celldblclick(sender, td, cellIndex, record, tr, rowIndex, e, eOpts)
{
var el=e.target.parentElement;
if($(el).hasClass("x-grid-td")&&!$(el).hasClass("x-grid-cell-special"))
{
sender.up('window').mask('loading...');
ajaxRequest(sender.up('window'),'grdDblClick',['indx='+record.get('1')]);
}
}