window enhancement

hi experts,

i tried to enhance the main window of the component BT117H_SRVC( this component has already been enhanced). however i didn't get option to enhance the main window. rather i could see already there is a option on the menu like delete enhancement. when i checked the class name of window. it started with CL*. so its standard one. but why it is not showing enhancement option. what could be the reason and how to solve it. kindly respond.