Private/ADLookups/_LoadCustomSources.ps1

function _LoadCustomSources {
    try {
        if ($AllUsers) {
            foreach ($User in $($AllUsers | Sort-Object Name)) {
                $ADLookups_UserTabSamAccountNameComboBox.Items.Add($User.SamAccountName)
                $ADLookups_UsersGroupsTabSamAccountNameComboBox.Items.Add($User.SamAccountName)
                $ADLookups_ExchangeTabSamAccountNameComboBox.Items.Add($User.SamAccountName)
            }
        }
        else {
        }

        if ($AllGroups) {
            foreach ($Group in $($AllGroups | Sort-Object Name)) {
                $ADLookups_GroupTabSamAccountNameComboBox.Items.Add($Group.Name)
            }
        }
        else {
        }

        if ($AllComputers) {
            foreach ($Computer in $($AllComputers | Sort-Object Name)) {
                $ADLookups_ComputerTabHostNameComboBox.Items.Add($Computer.Name)
            }
        }
        else {
        }
    }
    catch {
        $MessageSplat = @{
            MessageText  = "Unable to load custom sources to combo boxes.`n$_"
            MessageIcon  = 'Hand'
            ButtonType   = 'OK'
            MessageTitle = 'Error'
        }
        _ShowMessageBox @MessageSplat
    }
}