Something

<script type="text/javascript"><!--
function setjs() {
if(navigator.product == 'Gecko') {
  document.loginform["interface"].value = 'mozilla';
}else if(navigator.appName == 'Microsoft Internet Explorer' &&
navigator.userAgent.indexOf("Mac_PowerPC") > 0) {
  document.loginform["interface"].value = 'konqueror';
}else if(navigator.appName == 'Microsoft Internet Explorer' &&
document.getElementById && document.getElementById('ietest').innerHTML) {
  document.loginform["interface"].value = 'ie';
}else if(navigator.appName == 'Konqueror') {
  document.loginform["interface"].value = 'konqueror';
}else if(window.opera) {
  document.loginform["interface"].value = 'opera';
}}
//-->

</script>