def if_page(page_class, params={:using_params => {}},&block)
      page_class = class_from_string(page_class) if page_class.is_a? String
      return @current_page unless @current_page.class == page_class
      on_page(page_class, params, false, &block)
    end
def if_page(page_class, params={:using_params => {}},&block)
      page_class = class_from_string(page_class) if page_class.is_a? String
      return @current_page unless @current_page.class == page_class
      on_page(page_class, params, false, &block)
    end
Create a page object if and only if the current page is the same page to be created

 @param [PageObject, String]  a class that has included the PageObject module or a string containing the name of the class
 @param Hash values that is pass through to page class a
 available in the @params instance variable.
 @param [block]  an optional block to be called
 @return [PageObject] the newly created page object