if(navigator.appVersion.indexOf("Mac") >= 1){

document.write('<STYLE TYPE="TEXT/CSS">\n');
document.write('<!--\n');
document.write('H1 {font-Size:18px;}\n');
document.write('H2 {font-Size:13px;}\n');
document.write('H3 {font-Size:12px;}\n');
document.write('-->\n');
document.write('</STYLE>\n');

}else{
document.write('<STYLE TYPE="TEXT/CSS">\n');
document.write('<!--\n');
document.write('H1 {font-Size:18px;}\n');
document.write('H2 {font-Size:14px;}\n');
document.write('H3 {font-Size:13px;}\n');
document.write('-->\n');
document.write('</STYLE>\n');
}