/// <summary>
/// Finds all enabled buttons in the specified window element.
/// </summary>
/// <param name="elementWindowElement">An application or dialog window.</param>
/// <returns>A collection of elements that meet the conditions.</returns>
AutomationElementCollection FindByMultipleConditions(
    AutomationElement elementWindowElement)
{
    if (elementWindowElement == null)
    {
        throw new ArgumentException();
    }
    Condition conditions = new AndCondition(
      new PropertyCondition(AutomationElement.IsEnabledProperty, true),
      new PropertyCondition(AutomationElement.ControlTypeProperty, 
          ControlType.Button)
      );

    // Find all children that match the specified conditions.
    AutomationElementCollection elementCollection = 
        elementWindowElement.FindAll(TreeScope.Children, conditions);
    return elementCollection;
}