how to made this in coldfusion

Try what I have below.  Pretty sure its what's you are try to do.  Hope this helps.  If it answers your question please mark as so, I'm new to these forums and I'd like to generate some points.

<script>
function myFunc(obj)
{
  document.getElementById('mySpan').innerHTML=''; //blank it out
  //loop through the options
  for (i=0; i <= obj.options.length - 1; i++)
  {
   if (obj.options.selected)
   {
    if (document.getElementById('mySpan').innerHTML == '') //first one, don't lead with comma
     document.getElementById('mySpan').innerHTML=obj.options.value;
    else
     document.getElementById('mySpan').innerHTML=document.getElementById('mySpan').innerHTML+', '+obj.options.value;
   }
  }
}
</script>

<select name="test" id="test" multiple="true" size="10" onclick="myFunc(this)">
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
<option value="4">Four</option>
<option value="5">Five</option>
<option value="6">Six</option>
<option value="7">Seven</option>
<option value="8">Eight</option>
<option value="9">Nine</option>
<option value="10">Ten</option>
</select>
<br>
You have selected: <span id="mySpan"></span>

i got that by using multiple options but i need to show user which options user selected just below that drop down

In addition to the multiple setting you may want to use size="10", then maybe a note to the side of the field letting the user know they can select multiples by holding down the "Ctrl" key.

Personally I prefer checkboxes but,

<select multiple="multiple">