Hi, Sylvain,

I think you're close...I believe you need one more line at the end, to actually bind/map a property of the combobox to the datatable.

cboClient.DataBindings.Add("SelectedValue",dtClient, ,"PK_Client");

This way, what's in the combo's SelectedValue (associated with ValueMember) will be mapped to PK_Client.

Let me know if that helps...
Kevin