What I have done is given below, but still now combobox is functioning, typing can be done in this combobox, 'Disabled' not done.
var colDate = $(this).datagrid('getColumnOption', 'CALDATE');
colDate.editor = {
type:'combobox',
options:{
method: 'get',
valueField:'ST_DT',
textField:'ST_DT',
panelHeight:100,
url: 'getDate.php?dt1='+cald1+'&dt2='+cald2+'&pc='+row.PROGCODE,
onLoadSuccess: function(data){
if (!data.length){
var ed = $(this).datagrid('getEditor', {index:index,field:'CALDATE'});
var combo = $(ed.target);
combo.combobox('disable');
}
}
}
};
Although in combobox there is no row displayed.