getting exception,when i'm trying to add only spaces values to select box dynamically.

getting exception,when i'm trying to add only spaces values to select box dynamically.

hi All,
i'm using below code to add values to select box.

    1. <%@

      page language="java"       contentType="text/html; charset=ISO-8859-1"

      pageEncoding="ISO-8859-1"%>

      <!

      DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

      <

      html>

      <

      head>

      <

      meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

      <

      script src="js/jquery.js"></script>

      <

      script type="text/javascript" src="js/jquery.appendToList.js"></script>

      <

      script type="text/javascript" src="js/editableControlList.doucument.ready.js">

      </

      script>

      <

      title>Editable Control List</title>

      </

      head>

      <

      body bgcolor="#CCCCCC">

      <

      form name="f1" >

      <

      div id="list">

      <

      table>

      <

      tr>

      <

      td>

      <

      table>

      <

      tr>

      <td>

      <span id="title" >Hobbies </span><img alt="Remove" src="Images/minus.png" align="right" id="remove"></img>

      </td>

      </tr>

      <

      tr><td><select size="10"  id="control_list" title="nazeer"></select></td></tr>

      <

      tr><td><input type="text" id="addelementvalue" /><img alt="Add" src="Images/plus.png" id="add"/></td></tr>

      <

      tr><td>Allow unique<input type="radio" name="isUnique" value="yes" checked="checked" >yes<input type="radio" name="isUnique" value="no">no </td></tr>

      <

      tr><td colspan="1"><span id="info" style="font-style: italic;">allows only unique values</span></td></tr>

      </

      table>

      </

      td>

      <

      td>

      </

      td>

      </

      tr>

      </

      table>

      </

      div>

      </

      form>

      </

      body>

      </

      html>

      the above code is html code and below code are js file.editableControlList.doucument.ready.js

      2. $(document).ready(

         function
      3. () {

      /*

      * when you click on add button appendToList method will call

      */

      $(

      '#add').click(function() {

      /*

      * calling appendToList method

      * value is a parameter represents text id

      * allowUniqvalues is a parameter represents radio button value(whether to allow unique values or not)

      * controllist is a parameter represents control list id

      */

      $(

      "#list").appendToList({value: '#addelementvalue',controllist: '#control_list',allowUniqvalues:$("input[name=isUnique]:checked").val()});

      return false;

      });
    jquery.appendToList.js                    
 
 
  1.  

    (function

 ($) {

$.fn.appendToList =

function (params) {

this .each( function () {

var $list=$(params.controllist);

var ctrlListLength=$(params.controllist+ ' option' ).length;

var $value=$.trim($(params.value).val());

var isThere=$list.find( 'option:contains(' +$value+ ')' ).val()==$value? true : false ;

var isUndefined=$list.find( 'option:contains(' +$value+ ')' ).val()=== undefined ? true : false ;

var isUniq=params.allowUniqvalues=="yes"? true : false ;

if($value==errors.noerror||$value==null)

{

alert("null values are not allowed");

return false;

}

else if ($.trim($value)==""||$.trim($value)==null)

{

alert("Only spaces not allowed");

return false;

}else

{

if (!isUniq)

{

$list.append(

 "<option value='" +$value+ "' alt='" +$value+ "' title='" +$value+ "'>" +$value+ "</option>" );

document.getElementById(params.value.substring(1)).value="";

}

 else if (isThere)

{

alert("duplicate not allowed");

 return false ;

}

 else

{

$list.append(

 "<option value='" +$value+ "' alt='" +$value+ "' title='" +$value+ "'>" +$value+ "</option>" );

document.getElementById(params.value.substring(1)).value="";

}

}

});

return this ;

};

})(jQuery);
 
    if i will enter only spaces to in text box and then if  i will click on add button,it's giving alert box like "Only spaces are not allowed ".
    If i will enter some values then i'm trying to add only spaces then i'm getting exception in jquery.js file how to resove it. and i'm using

    jquery 1.4.4 version

    error pic is
    Please any one give solution
    Thanks,
    Nazeer