function chgRankMenu( rankid ) {
	if(!(document.getElementById( 'contents' ) && document.getElementById( 'caststaff' ) 
		&& document.getElementById( 'tab_contents' ) && document.getElementById( 'tab_caststaff' ))) {
		return 0;
	}

	document.getElementById( 'contents' ).style.display= "none";
	document.getElementById( 'caststaff' ).style.display= "none";

	document.getElementById( 'tab_contents' ).className= "contents_off";
	document.getElementById( 'tab_caststaff' ).className= "caststaff_off";


	if( document.getElementById( rankid ) && document.getElementById( 'tab_' + rankid ) ) {
		document.getElementById( rankid ).style.display = "block";
		document.getElementById( 'tab_' + rankid).className = rankid + "_on"
	} else {

	}

}