var tgs = new Array( 'div','td','tr');

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 ];
     }
 }