I live in an apartment and have a lax landlord. The windows are double hung vinyl - the kind that open from the top or bottom and swing in so that you may clean them from the inside. The clips that keep the window in the frame (when not swung in) are made of a cheap plastic and break; I am afraid my windows will blow in when they are open (only locking the windows when closed keeps them secure). I'd like to replace these clips but am not sure what they are called (they are screwed to the top of the bottom pane frame on either side), if they are universal or brand-specific, or even come in a sturdier material. Anyone know what these are called?