function changeFont(intFontSize) {

// intFontSize: 1, 2, 3 for class: font1, font2, font3 (default is 1)

// change "content" class name
document.getElementById("content").className='content font'+intFontSize;

// change "font" image
for (i=1;i<4;i++) {
 if (i == intFontSize) {
  document.getElementById('icon_font'+i).src="js/icon_font"+i+"_on.gif";
 }
 else {
  document.getElementById('icon_font'+i).src="js/icon_font"+i+"_off.gif";
 }
}
 
}