Stored procedure for arabic letters

create procedure [dbo].[Updateproject]
@ProjectID int,
@Title nchar(10) ,
@Description text ,
@DueBy datetime ,
@Status nvarchar(50)
as
update dbo.uni_project set Status=@Status,Title=@Title,Description=@Description,DueBy=@DueBy where projectID = @ProjectID
return 0
GO

string str = ConfigurationManager.ConnectionStrings["my"].ConnectionString;
                using (SqlConnection sqlcon = new SqlConnection(str))
                {
                    using (SqlCommand cmd = new SqlCommand("Createproject", sqlcon))
                    {
                        cmd.CommandType = CommandType.StoredProcedure;
                        cmd.Parameters.AddWithValue("Title", txtTitle.Text);
                        cmd.Parameters.AddWithValue("Description", txtData.Text);
                        cmd.Parameters.AddWithValue("DueBy", cbDate.Text);
                        cmd.Parameters.AddWithValue("username", txtusername.Text);
                        
                        sqlcon.Open();
                        cmd.ExecuteNonQuery();
                        MessageBox.Show("reminder set for" + cbDate.Text);
                    }
                }

update dbo.uni_project set Status=@Status,Title=N+@Title,Description=N+@Description,DueBy=@DueBy where projectID = @ProjectID