title: How can I set postData._search to true in the request in jqGrid?
body: <p>While I've been able to add my own post data programmatically, I cannot seem to figure out how to get this code to send <code>_search: true</code> in the request.</p>
  
  <pre><code>var data = grid.jqGrid("getGridParam", "postData");
  data._search = true;
  data.searchString = id.toString();
  data.searchOper = "eq";
  data.searchField = "userid";
  grid.jqGrid("setGridParam", { "postData": data });
  grid.trigger("reloadGrid");
  </code></pre>
  
  <p>The fields are added correctly, but somewhere along the way _search appears to be set to false, because every request has it set to false.  Is there some other thing I have to do to have it "true"?  I'm running a toolbar search, but most of the time when this code will be called there's nothing entered, and a decent chunk of utility code on my server checks _search before handling searches.</p>