title: jqgrid post request data json
body: <p>My grid data read is configured for use json format.
  This is the configuration</p>
  
  <pre><code>    url:"devitem.json",
      mtype: "POST",
      datatype: "json",
  
      ajaxGridOptions: {
        type    : 'post',
        async   : false,
        error   : function() { alert('Something bad happened. Stopping');},
      },
  
      jsonReader : {
        root        : "rows",
        page        : "page",
        total       : "total",
        records     : "records",
        repeatitems : true,
        cell        : "cell",
        id          : "0",
        userdata    : "userdata",
      },
  </code></pre>
  
  <p>The read request from client send always parameters in this format:</p>
  
  <p>_search=false&amp;nd=1317286048991&amp;rows=25&amp;page=1&amp;sidx=device_id&amp;sord=asc&amp;totalrows=100
  How I can convert it to json format ?</p>
  
  <p>I have also set the postData option</p>
  
  <pre><code>postData    : JSON.stringify({"dev_post_reqtype":"read","dev_post_devndx":"1","dev_post_reccount":"55"}),
  </code></pre>
  
  <p>It work but obiuovsly cannot be changed </p>
  
  <p>I have this problem with pager. For testing after change the page number I call this function</p>
  
  <pre><code>    function DEVpager_event(pgevent) {
  
   var page = jQuery("#DEVtbl").getGridParam('page');
    alert (pgevent+page) ;
  
  // changed devndx for test only
  var jdata = JSON.stringify({"dev_post_reqtype":"read","dev_post_devndx":"25","dev_post_reccount":"55"}) ;
  </code></pre>
  
  <p>jQuery("#DEVtbl").jqGrid('setGridParam', 'postData', jdata);
      } ;</p>
  
  <p>page is changed with my selection but postData don't change 
  thanks for help</p>