title: getting value from checked checkbox in ajax
body: <p>I want to get the values of the checked checkbox here but it is undefined because it becomes an array.. Please help me how to do it.. thank you.. </p>
  
  <pre><code>&lt;form&gt;
  &lt;input type="checkbox" value="a" name="letter[]" /&gt;
  &lt;input type="checkbox" value="b" name="letter[]" /&gt;
  &lt;input type="checkbox" value="c" name="letter[]" /&gt;
  &lt;input type="button" value="submit"  onclick="rani()" /&gt;
  &lt;/form&gt;
  &lt;script&gt;
  function rani(){
      $.ajax({
          type:"post",
          url:"ajax.php",
          data:{
              radha:$("[name=letter]").val(),
              },
          success:function(msg){
              alert(msg);
              }
          })
      }
  &lt;/script&gt;
  </code></pre>