Question

So I have two multiple select boxes like this

<select id="foo" multiple="multiple">
    <option value="1">Option 1</option>
    <option value="2">Option 2</option>
</select>

<select id="bar" multiple="multiple">
    <option value="1">Opt 1</option>
    <option value="2">Opt 2</option>
    <option value="3">Opt 3</option>
    <option value="4">Opt 4</option>
</select>
<a href="#" onclick="select()">Select</a>

What I’m trying to do is that when ‘Select’ is clicked, any option in “#bar” that has the same value with an option in “#foo” would be selected. In this case Opt 1 and Opt 2 in “#bar” should be selected.
I’ve no idea why my javascript won’t work. I know it must be something very simple. I just can’t see it. 🙁
So my Javascript function is as followed:

function select(){
    var vals = new Array();
    var iter = 0;
    $("#foo option").each(function(){
        var v = $(this).val();
        $('#bar option').each(function(){
            if ($(this).val() == v)
            {
                vals[iter] = v;
                iter++;
                break;
            }
        });
    });
    $("#bar").val(vals);
 }

Answer 1

UPDATE after seeing KON’s example

DEMO

$("#sel").click(function(e) {
  e.preventDefault(); // cancel the link itself
  $("#bar").val($("#foo").val());
});

---

<a href="#" id="sel">Select</a>

---

Older example using each

DEMO

$("#sel").click(function(e) { // when link clicked
  e.preventDefault();
  $("#foo option:selected ").each(function(){
    var v = $(this).attr("value"); // first select's value
    $('#bar option').each(function(){
      if ($(this).attr("value") == v) { 
        $(this).attr("selected",true); // select if same value
      }
    });
  });
})