Export datagrid in silverliht4

Here I am getting the error as "Current context not supported"

private void ExportExcel(object sender, RoutedEventArgs e)
{
try
{
int rowIndex = 1;
int coulmnIndex = 1;


dynamic excel = AutomationFactory.CreateObject("Excel.Application");

excel.workbooks.Add();

dynamic sheet = excel.ActiveSheet;

for (int i = 0; i < DataGrid.Columns.Count; ++i)
{
dynamic headerCell = sheet.Cells[rowIndex, coulmnIndex + i];
headerCell.Value = DataGrid.Columns[i].Header;
headerCell.Font.Bold = true;
headerCell.Interior.Color = 0xFF00;
}
PagedCollectionView well = model.Wells;
foreach (Well att in well.SourceCollection)
{
rowIndex++;

//column 1
dynamic cellFirstName = sheet.Cells[rowIndex, 1];

cellFirstName.Value = att.EngineeringComment;
cellFirstName.Font.Color = 003399;

//column 2
dynamic cellLastName = sheet.Cells[rowIndex, 2];
cellLastName.Value = att.Name;
cellLastName.Font.Color = 003399;

//column 3
dynamic cellAge = sheet.Cells[rowIndex, 3];
cellAge.Value = att.ChokePosition;
cellAge.Font.Color = 003399;

//column 4

dynamic cellSubscribed = sheet.Cells[rowIndex, 4];
cellSubscribed.Value = att.GasMRP;
cellSubscribed.Font.Color = 003399;

// Column5

dynamic cellSubscrib = sheet.Cells[rowIndex, 4];
cellSubscrib.Value = att.InterventionStatus;
cellSubscrib.Font.Color = 003399;

}
excel.Visible = true;
}
catch (Exception ex)
{
MessageBox.Show("Error generating excel: " + ex.Message);
}
}