Avoiding crystal report user name and password

private void btnshow_Click(object sender, EventArgs e)
        { 
            
            SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings   
            ["ConnectionString"]);
            conn.ConnectionString = "Data Source=USER-PC;Initial Catalog=MUCGPROJECT;User  
            ID=sa;Password=mike";
           
            
     SqlCommand cmd = new SqlCommand(string.Format("SELECT * FROM tblCollectorsRegistration     
            WHERE Collectorid='{0}'", this.txtCollectorid.Text), conn);
                conn.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                
                if (dr.HasRows)
                {
                    conn.Close();
                    DataTable tbl = new DataTable();
                    conn.Open();
    SqlDataAdapter adp = new SqlDataAdapter("SELECT Collectorid, Title, Surname, Firstname, 
                    Middlename, Gender, Dateofbirth, Nationality, Religion, Maritalstatus,   
                    Spousename, Telephone, Postaladdress, Residentialaddress, Hometownaddress  
                    from tblCollectorsRegistration WHERE Collectorid = '" +     
                    this.txtCollectorid.Text + "'", conn);
                    
                    adp.Fill(tbl);
                    rptCollectorindividual objRpt = new rptCollectorindividual();
                    objRpt.Database.Tables[0].SetDataSource(tbl);
                    crystalReportViewer1.ReportSource = objRpt;
                    crystalReportViewer1.Refresh();
                }
                else
                {
                    // Id already present
                    MessageBox.Show("The Collector ID does not Exist");
                    return;
                   
                }
        }