var tabNews_on = new Array() ;
var tabNews_off = new Array() ;
for( i=1; i<=3; i++ ) { 
    tabNews_on[i] = new Image() ;
    tabNews_on[i].src = 'img/news_box_0' + i + '.gif' ;
    tabNews_off[i] = new Image() ;
    tabNews_off[i].src = 'img/news_box_0' + i + '_o.gif' ;
}

var tabNewsImgName, tabNewsLayName;

function tabNewsAct() {
    for( i=1; i<=3; i++ ) {
        tabNewsImgName = 'tabNews' + i ;
        document.images[tabNewsImgName].src = tabNews_off[i].src ;
        tabNewsLayName = document.all['tabNewsLay'+i] ;
        tabNewsLayName.style.display = 'none' ;
    }
    tabNewsImgName = 'tabNews' + arguments[0] ;
    document.images[tabNewsImgName].src = tabNews_on[arguments[0]].src ;
    document.all['tabNewsLay'+arguments[0]].style.display = '' ;
}