jQuery Grid Plugin - jqGrid

I'm having a similar issue.  I'm trying to get the grid to be hidden initially but then not hidden when an option is clicked on in a select box.  Right now, the grid is hidden when the page is loaded, but it stays hidden, and I can't get it to be shown unless I click the arrow in the top right corner.  Here is a basic version of my code:

<script language="JavaScript">
  
  function ElementWidth(elem)
  {
    var w = $(elem).outerWidth() -(8*5)-2
    alert(w);
    return w;
  }
       
  function ChangeWarehouse()
  {
    var warehouse;
    var surl;
    warehouse = document.getElementById("warehouse").value;
    if(warehouse=="")
    {
      warehouse="0";
    }
    surl ="RINVINQW2?warehouse="+warehouse;
    $('#results').setGridParam({url:surl, hiddengrid:false});
    $('#results').trigger("reloadGrid");
  }   
   
  $(document).ready(function()
  {
    $('#warehouse').focus();
    var columnNames = ['id','Customer','Quantity','Value'];
    var columnModel =
    [
      {name:'id', hidden:true, index:'id'},
      {name:'customer', resizable:false, index:'customer', width:300, align:'left'},
      {name:'quantity', resizable:false, index:'quantity', width:130, align:'center'},
      {name:'value', resizable:false, index:'value', align:'center', width:130},
    ];
               
    var gridwidth = $('.tableContainer').width();
    gridwidth = gridwidth-26;

    $("#results").jqGrid(
    {
      url: "rinvinqw2?warehouse="+document.getElementById("warehouse").value,
      datatype: "json",
      mtype: 'GET',
      gridstate: 'hidden',
      colNames: columnNames,
      colModel: columnModel,
      viewrecords: true,
      width: gridwidth,
      height: '350px',
      loadComplete: function()
      {
        var udata = $('#results').getUserData();
        $('#t_results').css("text-align","right").html("...");
        $('#cb').prev().remove();
        if($('#results').getGridParam("records")==0)
        {
          $('#noResults').dialog("open");
        }
        else
        {
          var page = $('#results').getGridParam("page");
          var records = $('#results').getGridParam("records");
          var recordsPP = $('#results').getGridParam("rowNum");
          var x = records/recordsPP;
          var returnArray = [];
          if(x < page)
          {
            iterLimit = records%recordsPP;
          }
          else
          {
            iterLimit = recordsPP;
          }
                           
          for(var i=1; i<=iterLimit; i++)
          {
           $('#'+i).children('td:first').next().addClass('link').css("cursor","pointer").css("color","blue").css("text-decoration","underline");
                               
            var ord = $('#'+i).children('td:first').next().text();
            $('#'+i).children('td:first').next().click(function()
            {
              ord = $(this).text();
              window.location.href = "RINVINQW2?warehouse="+warehouse;
            });
          }
        }
      },
                   
      subGrid: true,
      subGridRowExpanded: function(subgrid_id, row_id)
      {   
        ...

      });

      shrinkToFit: true,
      jsonReader:
      {
        root: "rows",
        page: "page",
        total: "total",
        records: "records",
        repeatitems : false
      }
    });
               
    function gridReload()
    {
      var warehouse = $('#warehouse').val();
     $('#results').setGridParam({url:"rinvinqw2?warehouse="+warehouse,page:1,hiddengrid:false}).trigger("reloadGrid");
    }
  });
</script>