//list of html tags to scan and modify font size
var htmlTags = new Array('td','tr','span','div','p');
//Specify possible font sizes, avoided using relative sizing in order to match style sheet values
//var fontSizes = new Array( 'xx-small','x-small','small','medium','large','x-large','xx-large' );
var fontSizes = new Array( '7pt','8pt','9pt','11pt','13pt');
var currentSize = 2;

function fontResize( targetID,inc ) {
          //if not supported by current browser (doesn't understand DOM) bail 
          if (!document.getElementById) return;
          var targElements = null,targetSize = currentSize,i,z,targTags;
          
          targetSize += inc;
          if ( targetSize < 0 ) targetSize = 0;
          if ( targetSize > 4 ) targetSize = 4;
          currentSize = targetSize;
          	
          //scan page for specific ID associated with HTML tag in Document Object Model, currently using a default ID "textBody" for all printable pages
          if ( !( targElements = document.getElementById( targetID ) ) ) targElements = document.getElementsByTagName( targetID )[ 0 ];
          targElements.style.fontSize = fontSizes[ targetSize ];
 
         for ( i = 0 ; i < htmlTags.length ; i++ ) {
               targTags = targElements.getElementsByTagName( htmlTags[ i ] );
               for ( z = 0 ; z < targTags.length ; z++ ) targTags[ z ].style.fontSize = fontSizes[ targetSize ];
          }
}