<script language="javascript" type="text/javascript">
function move(formObj,toObj){
if(formObj.selectedIndex != -1){
toObj.add(new Option(formObj.options[formObj.selectedIndex].text,formObj.options[formObj.selectedIndex].value));
formObj.remove(formObj.selectedIndex);
//var index = formObj.selectedIndex;
}
}
</script>
<form name="form1">
<table>
<tr>
<td>
<select multiple name="left" size=7 οndblclick="move(this,this.form.right)">
<option value="0" selected>item1</option>
<option value="1">item2</option>
<option value="2">item3</option>
<option value="3">item4</option>
<option value="4">item5</option>
</select>
</td>
<td >
<input type="button" name="moveRigth" value=">>" οnclick="move(this.form.left,this.form.right)"/>
<input type="button" name="moveLeft" value="<<" οnclick="move(this.form.right,this.form.left)"/>
</td>
<td>
<select multiple name="right" size=7 οndblclick="move(this,this.form.left)">
<option value="0" selected>test1</option>
<option value="1">test2</option>
<option value="2">test3</option>
<option value="3">test4</option>
<option value="4">test5</option>
</select>
</td>
</tr>
</table>
</form>