Invoke webharvest function from JavaScript function

Question

I have created a webharvest function. I am able to invoke the function using webharvest code. My challenge is, need to invoke that webharvest function from a JavaScript function. Is it possible? For example, consider this:

Webharvest method

 <function name="testing">  
   <script>
   // <![CDATA[
       // code block    
   // ]]>
   </script>

JavaScript method

<script>
  // <![CDATA[
  function jMethod(){
    testing(); // need to call that web harvest method here
  }
  // ]]>
</script>