function changemenu (menuid)
{
	clearbold('menu1');
	clearbold('menu2');
	clearbold('menu3');		

  verbergen('menu1');
	verbergen('menu2');	
	verbergen('menu3');
   	
	maakzichtbaar(menuid);
   
	firstsub=document.getElementById(menuid + "_1");
//	parent.frames['mainFrame'].location.href=firstsub.href;
	firstsub.style.fontWeight="bold";
}

function makebold (submenu)
{
	myid=submenu.id;
    	
	thismenu=myid.substring(0,myid.indexOf("_"));
	  	
	clearbold(thismenu);
	
	submenu.style.fontWeight="bold";

}

function clearbold (menu)
{

	i=1;
	myvar=true;
	while (myvar==true)
		{
			if (document.getElementById(menu+"_" + i)!=null)
			{
				othersubmenu=document.getElementById(menu+"_" + i);
				othersubmenu.style.fontWeight="";
			}
			else
			{
				myvar=false;
				
				break;
			}
			i++;
		}	
}