rosa-build/app/assets/javascripts/design/radio.js

$(document).ready(function(){
  $(".niceRadio").each(function() {
    changeRadioStart($(this));
  });
});

function changeRadio(el) {
  var el = el, input = el.find("input").eq(0);
  var nm = input.attr("name");

  $(".niceRadio input").each(

  function() {
    if($(this).attr("name")==nm) {
      $(this).parent().removeClass("radioChecked");
    }
  });

  if(el.attr("class").indexOf("niceRadioDisabled")==-1) {
    el.addClass("radioChecked");
    input.attr("checked", true);
  }

  return true;
}

function changeVisualRadio(input) {

  var wrapInput = input.parent();
  var nm=input.attr("name");

  $(".niceRadio input").each(function() {
    if($(this).attr("name")==nm)
    {
      $(this).parent().removeClass("radioChecked");
    }
  });

  if(input.attr("checked")) 
  {
    wrapInput.addClass("radioChecked");
  }
}

function changeRadioStart(el) {

  try {
    var el = el,
      radioName = el.attr("name"),
      radioId = el.attr("id"),
      radioChecked = el.attr("checked"),
      radioDisabled = el.attr("disabled"),
      radioTab = el.attr("tabindex"),
      radioValue = el.attr("value");

      if(radioChecked) {
        el.after("<span class='niceRadio radioChecked'>"+
          "<input type='radio'"+
          "name='"+radioName+"'"+
          "id='"+radioId+"'"+
          "checked='"+radioChecked+"'"+
          "tabindex='"+radioTab+"'"+
          "value='"+radioValue+"' /></span>");
      } else {
        el.after("<span class='niceRadio'>"+
          "<input type='radio'"+
          "name='"+radioName+"'"+
          "id='"+radioId+"'"+
          "tabindex='"+radioTab+"'"+
          "value='"+radioValue+"' /></span>");
      }

      if(radioDisabled) {
        el.next().addClass("niceRadioDisabled");
        el.next().find("input").eq(0).attr("disabled","disabled");
      }

      el.next().bind("mousedown", function(e) {
        if (e.which === 0) {
            changeRadio($(this));
        };
        $(this).find("input:radio").change();
      });
      if($.browser.msie) {
        el.next().find("input").eq(0).bind("click", function(e) {
          changeVisualRadio($(this)) 
        });
      } else {
        el.next().find("input").eq(0).bind("change", function(e) {
          changeVisualRadio($(this))
        });
      }
      el.remove();
  }

  catch(e) { }

  return true;
}