Get selected values in a multi-select drop-down with JavaScript

 var hexvalues = [];

var labelvalues = [];

$('#myMultiSelect :selected').each(function(i, selectedElement) {
 hexvalues[i] = $(selectedElement).val();
 labelvalues[i] = $(selectedElement).text();
});

Get selected get customer attribute drop-down with JavaScript

 

<select id="location">
    <option value="a" myTag="123">My option</option>
    <option value="b" myTag="456">My other option</option>
</select>

alert($('#location').find('option:selected').attr('myTag'));