events

      attributes for common UI events
      onclick     a pointer button was clicked
      ondblclick  a pointer button was double clicked
      onmousedown a pointer button was pressed down
      onmouseup   a pointer button was released
      onmousemove a pointer was moved onto the element
      onmouseout  a pointer was moved away from the element
      onkeypress  a key was pressed and released
      onkeydown   a key was pressed down
      onkeyup     a key was released