<script type="text/javascript">     function openDialog(){         paramers="dialogWidth:500px; dialogHeight:300px; status:no";         workerId = window.showModalDialog("userList.aspx","",paramers);         if(workerId!=undefined && workerId!=""){             document.getElementById("leader").value = workerId;           }         } </script>

<input type="button" value="选择" onclick="javascript:selectPositionAndClose();"/>     </form> <script type="text/javascript">     function selectPositionAndClose(){         var obj = document.getElementById("userList");         var user = "";         for(var i=0;i<obj.options.length;i++){             if(obj.options[i].selected==true){                 user = obj.options[i].value;             }         }         window.returnValue = user;         window.close();     } </script>