Data grid problem

1

I am inserting data in dataGrid
"
var dp = myGrid.dataProvider;
for (var i in myvar.data)
{
dp.push({slotName: i});

	}

"
**it is inserting data very fine in the grid (displaying fine on stage) , but I am unable to access **

I am trying
"
trace(dp.getItemAt(0).data);
trace(dp.getItemAt(1).data);
"
or

"
trace(myGrid.getItemAt(0).data);
trace(myGrid.getItemAt(1).data);
"

but it displays UNDEFINED