title: On change radio button state show submit button... how?
body: <p>I want to show a submit button only when the radio button value change. I will have several radio groups and the button should appear if any radio button change! Also, if radio button group value gets to default value submit button will hide again.</p>
  
  <pre><code>$("form :radio").live('change',function(){
  
  });
  </code></pre>
  
  <p>My new code:</p>
  
  <pre><code>//hide the submit button on load
          $('form :submit').hide();
  
          //Data structure where the initial value from radio button(s) will be stored
          var dbRadios = [];
  
          //Getting the initial values from the radio button(s) and load them to the data structure
          $("form :radio:checked").each(function() {
              dbRadios.push($(this).attr('value'));
          });
  
  
          //Attach onclick event to radio button(s)
          $('form :radio').click(function() {
  
              //The event fired, therefore the "New value(s)" (radio button value(s))  will be stored in the data sctructure
              var submitedRadios = [];
  
              //Geting the values from checked radio buttons
              $("form :radio:checked").each(function() {
                  submitedRadios.push($(this).attr('value'));
              });
  
              //Now comparing both data structures
              if(dbRadios.compare(submitedRadios)){
                  $('form :submit').fadeOut('slow');
              }else{
                  $('form :submit').fadeIn('slow', function(){ ACTION! WILL BE EXECUTED MANY TIMES AS BUTTONS CLICKED});
              }
  
          });
  
  
          $("form").submit(function () {
          //AJAX GOES HERE!   
          alert("a submeter dados");  
          })
  </code></pre>
  
  <p>The compare function:</p>
  
  <pre><code>//Compare two different arrays
      Array.prototype.compare = function(testArr) {
          if (this.length != testArr.length) return false;
          for (var i = 0; i &lt; testArr.length; i++) {
          if (this[i].compare) { 
              if (!this[i].compare(testArr[i])) return false;
          }
          if (this[i] !== testArr[i]) return false;
          }
          return true;
      }
  </code></pre>