Cannot resolve the collation conflict between "Latin1_General_CI_AI" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation.

listBox1.Items.Clear();         
            cmd = new SqlCommand("SELECT SimNo FROM PurchaseEntry AS t1 WHERE country ='" + cmbcountry.SelectedItem.ToString() + "'and (IMEINo = 'N/A')and  (SimNo NOT IN   (SELECT others FROM challanout AS t2 )) and status!='"+"IN USE"+"'", con);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds, "cout");
            int i = ds.Tables[0].Rows.Count;
            for (int t = 0; t < i; t++)
            {
                listBox1.Items.Add(ds.Tables[0].Rows[t][0].ToString());
                listBox1.Width = cmbitemtype.Width;
                listBox1.Height = Convert.ToInt32(listBox1.ItemHeight * i) + 10;
            } 

da.fill

Cannot resolve the collation conflict between "Latin1_General_CI_AI" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation.