function but_rollover(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navtop/bt_"+nummer+"_over.jpg";
}

function but_back(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navtop/bt_"+nummer+".jpg";
}

function but_back_aktiv(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navtop/bt_"+nummer+"_aktiv.jpg";
}



function but_rollover_help(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navhelp/bt_"+nummer+"_over.jpg";
}

function but_back_help(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navhelp/bt_"+nummer+".jpg";
}

function but_back_aktiv_help(nummer){
document.getElementById(nummer).src="fileadmin/templates/images/navhelp/bt_"+nummer+"_aktiv.jpg";
}