//salve com o nome por texto:
    var tgs = new Array( 'div','td','tr');

    //Specify spectrum of different font sizes:
    var szs = new Array( 'xx-small','x-small','small','medium','large','x-large','xx-large' );
    var startSz = 2;

    function ts( trgt,inc ) {
       if (!document.getElementById) return
       var d = document,cEl = null,sz = startSz,i,j,cTags;
       
       sz += inc;
       if ( sz < 0 ) sz = 0;
       if ( sz > 6 ) sz = 6;
       startSz = sz;
          
       if ( !( cEl = d.getElementById( trgt ) ) ) cEl = d.getElementsByTagName( trgt )[ 0 ];

       cEl.style.fontSize = szs[ sz ];

       for ( i = 0 ; i < tgs.length ; i++ ) {
          cTags = cEl.getElementsByTagName( tgs[ i ] );
          for ( j = 0 ; j < cTags.length ; j++ ) cTags[ j ].style.fontSize = szs[ sz ];
       }
    }