[NTG-context] How to prevent header at page bottom

Hi, I have defined my own header: \definehead[myhead][subsection] \setuphead[myhead][ page=no, number=no ] All works fine, except sometimes the head appears at page bottom and the text starts on the next page. How can I specify that if less than, say, 3 lines of text fit on the current page below the head, the head and text should start on the next page. Thanks in advance, Jos