SharePoint

I'm using the following script (found on line) to disable a multi-line text box form field control on a custom EditForm.aspx page using SharePoint Designer:

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>
<script type="text/javascript">

$(document).ready(function() {
    // add change handler
    $("input[title='chkBox']").change(function() {
        MasterSelectChange();
    });
    // call the change function to set up form for first display:
    MasterSelectChange();
});

function MasterSelectChange()
{
    var thisVal =  $("input[ID='chkBox']").val();
    if(thisVal == "True")
    {
     $("select[ID='Comments']").enabled="True";    
      }
    else
    {
      $("select[ID='Comments']").enabled="False";
    }
}
</script>


I don't get an error and can't figure out why it isn't working.  Does anyone have a similar solution or see why this script won't work?

Thanks!

<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Workflow

     Name="Site - Share"

     Description="My SharePoint Workflow"

     Id="48eccd6e-3efb-476f-9d33-e47e5fcbd136"

     CodeBesideClass="Site.Workflow1.Workflow1"

     CodeBesideAssembly="$assemblyname$"

     AssociationUrl="_layouts/CstWrkflIP.aspx"

     >
    <Categories/>
    <MetaData>
      <AssociationCategories>Site</AssociationCategories>
      <Association_FormURN>urn:schemas-microsoft-com:office:infopath:infoPathSample:-myXSD-2013-03-11T22-06-19</Association_FormURN>
      <StatusPageUrl>_layouts/WrkStat.aspx</StatusPageUrl>
    </MetaData>
  </Workflow>
</Elements>

<?xml version="1.0" encoding="utf-8" ?>
<Feature xmlns="http://schemas.microsoft.com/sharepoint/"

ReceiverAssembly="Microsoft.Office.Workflow.Feature,Version=14.0.0.0, Culture=neutral,PublicKeyToken=71e9bce111e9429c" 

ReceiverClass="Microsoft.Office.Workflow.Feature.WorkflowFeatureReceiver" >
  <Properties>
    <Property Key="GloballyAvailable" Value="true" />
      <Property Key="RegisterForms" Value="Workflow1\*.xsn"/>
  </Properties>
</Feature>

<%@ Register Tagprefix="DemoVisualWebPart" Namespace="SiteDefinitionProject1.VisualWebPart1"

Assembly="$SharePoint.Project.AssemblyFullName$" %>


  <DemoVisualWebPart:DemoVisualWebPart runat="server" ID="DemoVisualWebPartUserControl1"

                                            Description="My Visual WebPart" Title="DemoVisualWebPart">
                                    </DemoVisualWebPart:DemoVisualWebPart>