[3D Bar chart with variable column in same chart]

hi,

i'm facing this problem, i want to generate a column chart with montly grouped bars.

the problem is that the number of bars for each month is a range starting from 0 going to N, so i can have a month with 0 bars and a month with N bars.

i generate the data from JSON with javascript :

 var data2 = [];

$.each(dati.mesiCommesse,function (index, mese){

var obj ={"Mese":mese.nomeMese};

//mese.orePerCommessa can contain 0 elements

$.each(mese.orePerCommessa,function (index, commessa){

obj[commessa.nomeCommessa] = commessa.oreDouble;

});

data2.push(obj);

});

chart2.setDataSource(data2);

in the chart i get a "no data avaible" message...how to solve ?