A system for controlling the display of pop-up windows in web browsers intercepts a request to display a pop-up window and instead may display a dialog box asking the user to indicate whether the user wishes to display the pop-up window. The bumper beam structure has a plurality of vertically long weak parts formed in a front surface of the bumper beam. In step a, a positive pressure is formed between a polishing pad and a wafer. 1 mM and 50 mM, is also disclosed. The annular protrusion is press-fitted and fixed to the polygonal enlarged recess.