How to set the 'selected option' of a select dropdown list with jquery

Question

I have the following jquery function:

$.post('GetSalesRepfromCustomer', {
    data: selectedObj.value
}, function (result) {
    alert(result[0]);
    $('select[name^="salesrep"]').val(result[0]);
});

result[0] is a value that I want to set as the selected item in my select box. result[0] equals Bruce jones.

the select box is populated by a database query but one of the rendered html is:

<select id="salesrep" data-theme="a" data-mini="true" name="salesrep">
<option value=""> </option>
<option value="john smith">john smith</option>
<option value="Bruce Jones">Bruce Jones</option>
<option value="Adam Calitz">Adam Calitz</option>
<option>108</option>
</select>

$('select[name^="salesrep"]').val(result[0]); doesn't populate the select box selected option. I have also tried $("#salesrep").val(result[0]); without any luck.

Any help appreciated.

so what I want is the selected / highlighted option in the salesrep dropdown list to be Bruce Jones.

HTML to be:

<select id="salesrep" data-theme="a" data-mini="true" name="salesrep">
<option value=""> </option>
<option value="john smith">john smith</option>
<option value="Bruce Jones" selected >Bruce Jones</option>
<option value="Adam Calitz">Adam Calitz</option>
<option>108</option>
</select>

Thanks again,

Entire Script

<script type="text/javascript"> 
    $(document).ready(function () {

           $("#customer").autocomplete( 
     { 
     source: "get_customers", 
     messages: 
     { 
     noResults: '', 
     results: function() {} 
     }, 
     select: function( event, ui ) 
     { 
      var selectedObj = ui.item;        

     $.post('GetSalesRepfromCustomer', {data:selectedObj.value},function(result) { 
      alert(result[0]);
       var selnametest="Bruce Koller";
    $("#salesrep").val(selnametest);
     }); 

     } 
     });
         });


</script>

Rendered HTML is:

<select id="salesrep" data-theme="a" data-mini="true" name="salesrep">
<option value=""> </option>
<option value="RyanLubuschagne">Ryan Lubuschagne</option>
<option value="Bruce Jones">Bruce Jones</option>
<option value="Adam Calitz">Adam Calitz</option>
</select>

Answer 1

Try this :

$('select[name^="salesrep"] option[value="Bruce Jones"]').attr("selected","selected");

Just replace option[value="Bruce Jones"] by option[value=result[0]]

And before selecting a new option, you might want to "unselect" the previous :

$('select[name^="salesrep"] option:selected').attr("selected",null);

You may want to read this too : jQuery get specific option tag text

Edit: Using jQuery Mobile, this link may provide a good solution : jquery mobile - set select/option values