title: find index of max value of associate array in jquery
body: <p>i have an array like this,and want to find index of maximum of value .for this sample it should return c1:</p>
  
  <pre><code>      var arr={
         c1:{val: 9, x: 2, y: 0}
         c2:{val: 1, x: 3, y: 0}
         c3:{val: 6, x: 4, y: 0}
          }
  </code></pre>