title: Delete row from one jqGrid and add it to another
body: <p>I have two jqGrids ("in_table", and "out_table") that are identical except for their data.  Thanks to help I received on <a href="https://stackoverflow.com/questions/11743983/adding-a-custom-button-in-row-in-jqgrid">this post</a>, I now understand how to add a customizable button.  When the button is pushed, I'd like to delete the row from the table and add it to the other.  </p>
  
  <p>The following code, which is called when the button is pushed, is unpredictable - it works for a while and then it stops working!<br>
  The console shows an error: </p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'name' of undefined 
  </code></pre>
  
  <p><strong>Code:</strong></p>
  
  <pre><code>function sign_in_out_action(myself,rowid,icol,cellcontent,e){
      var this_row = myself.getRowData(rowid);
      if( in_out_button_content(cellcontent)== "In"){
      alert('Signing OUT');
      this_row.in_out = "Out";
      $('#out_table').jqGrid('addRowData',1,this_row);
      myself.delRowData(rowid);
      }
      else{
      if( in_out_button_content(cellcontent)== "Out"){
          alert('Signing in');
          this_row.in_out = "In";
          $('#in_table').jqGrid('addRowData',1,this_row);
          myself.delRowData(rowid);
      }
      else{
          alert("what?  "+in_out_button_content(cellcontent));
      }
      }
  </code></pre>
  
  <p>It would seem pretty straightforward to delete and add data.   I would appreciate any insight into what I am doing wrong.</p>