function uncheck(input, id) {
   if (document.getElementById) {
      var radio = document.getElementById(input+id);
      var temp = document.getElementById(input+'_temp');
   } else if (document.all) {
      var radio = document.all[input+id];
      var temp = document.all[input+'_temp'];
   } else {
      if ((navigator.appname.indexOf("Netscape") != -1) && parseInt(navigator.appversion == 4)) {
         var radio = document.layers[input+id];
         var temp = document.layers[input+'_temp'];
      }
   }
   if(radio.value == temp.value) {
      radio.checked = false;
      temp.value = '';
   } else {
      temp.value = radio.value;
   }
}