function menu_link(num){	switch(num)	{	  case 1:window.location="index.html" ;break;	  case 2:window.location="what.html" ;break;	  case 3:window.location="how.html" ;break;	  case 4:window.location="faq.html" ;break;	  case 5:window.location="buy.html" ;break;	}}