//Specify affected tags. Add or remove from list:
var tgs = new Array( 'p' );
var tgso = new Array( 'strong' );
var tgsu = new Array( 'font' );
var tgsa = new Array( 'div' );
var tgse = new Array( 'span' );

//Specify spectrum of different font sizes:
var szs = new Array( 'xx-small','x-small','small','medium','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 ];
}

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

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

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

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

}