Calculate total amount of a column in a subgrid after Rollup 12

Hi

We have used the following javascript to calculate the total from a column in a subgrid and put the value in another field. 

function CostoTotal(){

var gridControl = document.getElementById('opportunityproductsGrid').control;
var ids = gridControl.get_allRecordIds();
var sum = 0.00;
for(i = 0; i < ids.length; i++) {
var cellValue = gridControl.getCellValue('new_costo', ids[i]);
cellValue = cellValue.replace( /,/,"." );
var sum = sum + parseFloat(cellValue);
}
Xrm.Page.getAttribute('new_costototal').setValue(sum);
}

However the code dont work after updating to rollup 12. 

Anyone know if its possible to this in another way that works after R12? 

thanks.