JQuery basic code

//Hook change for each option to an event

<asp:Content ContentPlaceHolderID="ScriptPlaceHolder" ID="Scripts" runat="server">

   <script type="text/jscript" language="javascript">

  $(document).ready(function () {

      $("#listSamples").change(function (event) {



          if (this.value == 'RunSampleA') {

              RunSampleA();

              return;

          }



          if (this.value == 'RunSampleB') {

              RunSampleB();

              return;

          }

          if (this.value == 'RunSampleC') {

              RunSampleC();

              return;

          }

          if (this.value == 'RunSampleD') {

              RunSampleD();

              return;

          }

      }

)

  }

  );

script>

asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

<div id="div_content">

  content;

  <select id="listSamples">

      <option value='NULL'>Choose Sampleoption>

      <option value='RunSampleA'>Run Sample Aoption>

      <option value='RunSampleB'>Run Sample Boption>

      <option value='RunSampleC'>Run Sample Coption>

      <option value='RunSampleD'>Run Sample Doption>

  select>

div>

asp:Content>