Column Order in Sharepoint Document Library

For 'column ordering' follow the below steps:

1. On libray "Settings" page, click on "Advanced settings" under "General Settings".

2. In "Content Types" section, select "Yes" for "Allow management of content types?".

3. Now, on "Settings" page, click on content type name (Document) under "Content Types".

4. On "List Content Type" page, click on "Column order" under "Columns" for changing the order of columns.

Adding SP Group Programatically and adding users to the group

 protected void btnCreateGroup_Click(object sender, EventArgs e)
        {
            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                using (SPSite selectedSubSite = new SPSite(ddlSubsite.SelectedValue))
                using (SPWeb selectedWeb = selectedSubSite.OpenWeb())
                {
                    SPUser owner=null;
                    if(selectedWeb.SiteAdministrators.Count>0)
                    {
                        owner = selectedWeb.SiteAdministrators[0];
                    }

                    else
                    {
                        owner = selectedSubSite.SystemAccount;
                    }

                    SPMember member =owner;
                    string[] gropuArray = new string[1];
                    gropuArray[0] = txtGroupName.Text;
                    SPGroupCollection groupCollection = selectedWeb.SiteGroups.GetCollection(gropuArray);
                    SPGroupCollection groups = selectedWeb.SiteGroups;
                    if (groupCollection.Count == 0)
                    {
                        groups.Add(txtGroupName.Text, member, owner, "test");
                    }
                    SPGroup newSPGroup = groups[txtGroupName.Text];
                    //Associate the group to the SPWeb.
                    //This will add the SPGroup to left side quicklaunch of Manage Groups page 
                    selectedWeb.AssociatedGroups.Add(newSPGroup);
                    selectedWeb.Update();
                    SPRoleDefinition role = selectedWeb.RoleDefinitions["Contribute"];
                    SPRoleAssignment roleAssignment = new SPRoleAssignment(newSPGroup);
                    roleAssignment.RoleDefinitionBindings.RemoveAll(); 

                    roleAssignment.RoleDefinitionBindings.Add(role);
                    //  selectedWeb.RoleAssignments.Add(roleAssignment); // this is applicable only for unique permission sites.
                    newSPGroup.Update();
                 selectedWeb.Update();
 
                      
                    }
                
            });

        }