This add(var a, var b) doesn't work. Why??? So simple funciton

This add(var a, var b) doesn't work. Why??? So simple funciton

<!DOCTYPE >
<html>
<head>

    <title>Loop through an array using jQuery</title>

    <script src="https://code.jquery.com/jquery-1.11.2.js"></script>
    <script type="text/javascript">
$(document).ready(function () {
  
  function myFunction( var a, var b) {   //Without var, the function works fine!!!!!!
       return a + b;
    }


    var m=0;


   $('# iknow').click(function(){
  
        m=m+1;
   var k = myFunction('king', m);
   alert(k);


  });
});
</script> 
</head>
<body>

    <button id ="iknow"> I know</button>
</body>
</html>