function menu_link(num)
{
	switch(num)

	{

	  case 1:window.location="catalog.htm" ;break;

	  case 2:window.location="http://www.bussim.biz" ;break;

	  case 3:window.location="minisim.htm" ;break;

	  case 4:window.location="instructor.htm" ;break;

	  case 5:window.location="students.htm" ;break;
	  
	  case 6:window.location="customerservice.htm" ;break;

	  case 7:window.location="links.htm" ;break;

	}
}