Get DNN User Roles for Dropdown List

public void GetRoles()
{
 DotNetNuke.Security.Roles.RoleController rc = new DotNetNuke.Security.Roles.RoleController();

 var myRoles = rc.GetRoles(this.PortalId);
 //  myRoles
 ddlRoles.DataSource = myRoles;
 ddlRoles.DataTextField = "RoleName";
 ddlRoles.DataValueField = "RoleName";
 ddlRoles.DataBind();

 // ADD FIRST (NULL) ITEM
 ListItem item = new ListItem();
 item.Text = "-- Select Role to Assign --";
 item.Value = "";
 ddlRoles.Items.Insert(0, item);
 // REMOVE DEFAULT ROLES
 ddlRoles.Items.Remove("Administrators");
 ddlRoles.Items.Remove("Registered Users");
 ddlRoles.Items.Remove("Subscribers");

 // REPORTS ROLE
 ddlReportsRoles.DataSource = myRoles;
 ddlReportsRoles.DataBind();

 // ADD FIRST (NULL) ITEM
 ListItem item1 = new ListItem();
 item1.Text = "-- Select Role to View Reports --";
 item1.Value = "";
 ddlReportsRoles.Items.Insert(0, item1);
 // REMOVE DEFAULT ROLES
 ddlReportsRoles.Items.Remove("Administrators");
 ddlReportsRoles.Items.Remove("Registered Users");
 ddlReportsRoles.Items.Remove("Subscribers");

 // MERGE ROLE

 ddlMergeRoles.DataSource = myRoles;
 ddlMergeRoles.DataBind();

 // ADD FIRST (NULL) ITEM
 item1.Value = "Select Role to Allow Merge";
 ddlMergeRoles.Items.Insert(0, item1);
 // REMOVE DEFAULT ROLES
 ddlMergeRoles.Items.Remove("Administrators");
 ddlMergeRoles.Items.Remove("Registered Users");
 ddlMergeRoles.Items.Remove("Subscribers");

}