//Specify affected tags. Add or remove from list:
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 ];
	}
}