Question I need advice ,, error with combobox have Parameters in DataGrid

[ebrahim]

hi
The idea is to make DataGrid contains a field of type combobox it have another data source to choose from those and save data in the DataGrid , this is possible and without any problems..
But when make Parameters to filter data in the combobox and when i try add records have different Parameters ,, error will appears.
An example may not be logical, but I hope that shows what I mean

link: https://rapidshare.com/files/2458729...erComboBox.zip

thanks