Prompt to close sketch. Displays a dialog box with thequestion, Close Sketch With Model Edges? if you create a sketchwith an open profile, then click Extruded Boss/Base to create aboss feature. Use the model edges to close the sketch profile andselect the direction in which to close the sketch

This is what is given in the help but how it works. Can't seeanything as its says a dialog box on my screen.SolidworksParts And Features