function ElementWidth(elem)
  {
   var w = $(elem).outerWidth() -(8*5)-2
   alert(w);
   return w;
  }
  
  function ChangeSalesRep()
  {
   var salesRep;
   var surl
   salesRep = document.getElementById("salesRepresentative").value;
   if(salesRep=="")
   {
    salesRep="0";
   }
   //alert(salesRep);
   surl = "RINVINQS2?salesRepresentative="+salesRep;
   $('#results').setGridParam({url:surl, hiddengrid:false});
   $('#results').setGridParam({hiddengrid:false});
   $('#results').trigger("reloadGrid");
  }
   
     $(document).ready(function()
  {
   var columnNames = ['Customer Name','Quantity','Value'];
         var columnModel =
   [
    {name:'id', resizable:false, index:'id', width:90, align:'left'},
    {name:'quantity', resizable:false, index:'quantity', width:40, align:'center'},
    {name:'value', resizable:false, index:'value', align:'center', width:40}
   ];
     
         var gridwidth = $('.tableContainer').width();
         gridwidth = gridwidth-26;
 
         $("#results").jqGrid(
   {
             url: "rinvinqs2?salesRepresentative="+document.getElementById("salesRepresentative").value,
    //hiddengrid:true,
             datatype: 'json',
    mtype: 'GET',
             colNames: columnNames,
             colModel: columnModel,
    pager: $('#pager2'),
    pgtext: ' of',
             rowNum: 50,
             rowList: [10,20,50,100],
             imgpath: "../javascript/JQGrid/themes/coffee/images",
             sortname: 'quantity',
    sortorder: "desc",
    viewrecords: true,
    caption: "Inventory Status By Sales Representative",
             width: gridwidth,
             height: '200px',
    multiselect: false,
             loadComplete: function()
    {
     var udata = $('#results').getUserData();
     $('#t_results').css("text-align","right").html("<table style=\\"width: 100%;\\"><tr><td style=\\"width: 277px; text-align: right;\\">Total: &nbsp;&nbsp;</td><td style=\\"width: 94px; text-align: center;\\"><!--%totohwgt%--></td><td style=\\"width: 63px; text-align: center;\\">100</td><td style=\\"width: 74px; text-align: center;\\"><!--%perLBCost%--></td><td style=\\"width: 122px; text-align: center;\\"><!--%totslswgt%--></td><td style=\\"width: 86px; text-align: center;\\"><!--%monthsSupply%--></td><td style=\\"width: 86px; text-aign: center;\\">&nbsp;&nbsp;&nbsp;&nbsp;</td></tr></table>");
     $('#cb').prev().remove();
     if($('#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 = "RINVINQS3?salesRepresentative="+document.getElementById("salesRepresentative").value;
       });
                     }
                 }
             },
    
    subGrid: true,  //If set to true this enables using a subgrid. If the subGrid is enabled, an additional column at left side is added to the basic grid. This column contains a 'plus' image which indicates that the user can click on it to expand the row. By default all rows are collapsed.
    subGridRowExpanded: function(subgrid_id, row_id)
    {
        // subgrid_id is an id of the div tag created within a table
        // the row_id is the id of the row
        // If we want to pass additional parameters to the url we can use
        // the method getRowData(row_id) - which returns associative array in type name-value
        // here we can easily construct the following
     
        var subgrid_table_id;
        subgrid_table_id = subgrid_id+"_t";
        jQuery("#"+subgrid_id).html("<table id='"+subgrid_table_id+"' class='scroll'></table>");
           jQuery("#"+subgrid_table_id).jqGrid(
     {
            url:"RINVINQS3?id="+row_id+"&salesRep="+document.getElementById("salesRepresentative").value,  //specifies program to retrieve cell data
            datatype: "json",  //type of returned data
                colNames: ['<div style="width: 100%; text-align: center;">Division<br />Number</div>','<br />Name','<div style="width: 100%; text-align: center;"><br />On Hand Weight</div>','<div style="width: 100%; text-align: center;">% of<br />Total</div>','<div style="width: 100%; text-align: center;">Per Lb<br />Cost</div>','<div style="width: 100%; text-align: center;">Avg Monthly<br />Sales Wgt</div>','<div style="width: 100%; text-align: center;">Months<br />Supply</div>','<div style="width: 100%; text-align: center;">Turnover<br />Rate</div>'],  //column names
              colModel:
      [
                {name:"divisionNumber",index:"divisionNumber",width:60,key:true,align:"center",sortable:false},
                {name:"divisionName",index:"divisionName",width:180,align:"left",sortable:false},
                {name:"onHandWeight",index:"onHandWeight",width:90,align:"center",sortable:false},
                {name:"percentOfTotal",index:"percentOfTotal",width:50,align:"center",sortable:false},          
                {name:"perLbCost",index:"perLbCost",width:50,align:"center",sortable:false},
       {name:"avgMonthlyWeight",index:"avgMonthlySales",width:80,align:"center",sortable:false},
       {name:"monthsSupply",index:"monthsSupply",width:60,align:"center",sortable:false},
       {name:"turnoverRate",index:"turnoverRate",width:60,align:"center",sortable:false},
                  ],
              //height: 100,  //height of subgrid
      width: 800,  //width of subgrid
              rowNum:20,  //number of rows to display initially in subgrid
              imgpath: "../javascript/JQGrid/themes/green/images",  //what theme to use with subgrid
              sortname: 'divisionNumber',  //initial sorted column name
              sortorder: "asc",  //initial sort order
      jsonReader:
      {
       repeatitems: false
      }               
        })
    },
   
          shrinkToFit: true,
          jsonReader:
    {
              root: "rows",
              page: "page",
              total: "total",
              records: "records",
              repeatitems : false
          }
      });
  });

I think you do not need to crate the grid every time you change the value from select box. Basically you need:

$(document).ready(function()
 {

$("#mygrid").jqGrid({...});

$('#salesRepresentative').change(function()
 {
        var salesRep = $(this).val();

#("#mygrid").setGridParam({...}).triggre("reloadGrid");

}

});

Regards

Tony

$('#table_id').setGridParam({url:”pgmname?parameter1=”+

  parameter1,page:1}).trigger(”reloadGrid”);   

When I insert this line into my selectbox's .change() function, the JS bombs out and gives the following error message:

$(”#table_id”).setGridParam is not a function

I'm currently at version 3.4.1.  Does anyone have an idea what might be causing this?

$(document).ready(function()
{
    $('#salesRepresentative').change(function()
    {
        var salesRep = $(this).val();
        var columnNames = ['Customer Name','Quantity','Value'];
        var columnModel =
        [
            {name:'id', resizable:false, index:'id', width:90, align:'left'},
            {name:'quantity', resizable:false, index:'quantity', width:40, align:'center'},
            {name:'value', resizable:false, index:'value', align:'center', width:40}
        ];
                   
        var gridwidth = $('.tableContainer').width();
        gridwidth = gridwidth-26;
   
        $("#results").trigger("reloadGrid").jqGrid(
        {
            url: "rinvinqs2?salesRepresentative="+$('#salesRepresentative').val(),  

            datatype: "json",
            mtype: 'GET',
            colNames: columnNames,
            colModel: columnModel, 
            pager: jQuery('#pager2'), 
            pgtext: ' of', 
            rowNum: 50, 
            rowList: [10,20,50,100], 
            imgpath: "../javascript/JQGrid/themes/coffee/images",
            sortname: 'quantity', 
            sortorder: "desc",
            viewrecords: true,
            caption: "Inventory Status By Sales Representative", 
            width: gridwidth,  
            height: '350px',  
            multiselect: false,  
            loadComplete: function()
            {
                var udata = $('#results').getUserData();
                $("#t_results").css("text-align","right").html("<table style=\\"width: 100%;\\"><tr><td style=\\"width: 277px; text-align: right;\\">Total: &nbsp;&nbsp;</td><td style=\\"width: 94px; text-align: center;\\"><!--%totohwgt%--></td><td style=\\"width: 63px; text-align: center;\\">100</td><td style=\\"width: 74px; text-align: center;\\"><!--%perLBCost%--></td><td style=\\"width: 122px; text-align: center;\\"><!--%totslswgt%--></td><td style=\\"width: 86px; text-align: center;\\"><!--%monthsSupply%--></td><td style=\\"width: 86px; text-aign: center;\\">&nbsp;&nbsp;&nbsp;&nbsp;</td></tr></table>");

                $('#cb').prev().remove();
                if($("#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 = "RINVINQS2?salesRepresentative="+salesRep;
                        });
                    }
                }
            },
                   
            subGrid: true, 
            subGridRowExpanded: function(subgrid_id, row_id)
            {   
                var subgrid_table_id;
                subgrid_table_id = subgrid_id+"_t";
                jQuery("#"+subgrid_id).html("<table id='"+subgrid_table_id+"' class='scroll'></table>");
                jQuery("#"+subgrid_table_id).jqGrid(
                {
                      url:"RINVINQS3?customerName="+row_id, 
                      datatype: "json",  //type of returned data
                      colNames: ['Item','Quantity','Unit Price','Value','Warehouse'], 
                      colModel:
                      [
                            {name:"item",index:"item",width:80,key:true},
                            {name:"quantity",index:"quantity",width:130},
                            {name:"unitPrice",index:"unitPrice",width:80,align:"right"},
                            {name:"value",index:"value",width:80,align:"right"},          
                        {name:"warehouse",index:"warehouse",width:80,align:"right",sortable:true},
                    ],

                      width: 800,
                      rowNum: 20,
                      imgpath: "../javascript/JQGrid/themes/coffee/images", 
                      sortname: 'item', 
                      sortorder: "desc",
                      jsonReader:
                      {
                          repeatitems: false
                      }                                   
                   })
            },
                                          
            shrinkToFit: true, 
            jsonReader :
            {
                root: "rows",
                page: "page",
                total: "total",
                records: "records",
                repeatitems : false
            } 
        });
    });
});