jQuery Grid Plugin - jqGrid

I have a onInitializeForm function that is supposed to pop up the datepicker on focus in the edit form. However it never pops up. I also don't see any JavaScript errors so I'm not sure what is happening.

Grid code as follows. Some of the bits are replaced by ASP.NET when this page is rendered (using the ASP.NET MVC Framework). The grid itself works great, just the date picker won't show.

<table id="list1" class="scroll">
    </table>

    <div id="pager1" class="scroll" style="text-align: center;">
    </div>
    <script type="text/javascript">
    var lastsel;
    $(document).ready(function(){
      $("#list1").jqGrid({
        url:'<%=Html.BuildUrlFromExpression<AnnouncementController>(c => c.ListJSON())%>',
        datatype: 'json',
        mtype: 'GET',
        altRows: true,
        hidegrid: false,
        toolbar: [true, 'top'],
        colNames:['Actions','Id', 'Date', 'Title', 'Text'],
        colModel :[
                    {name:'act',index:'act', width:75,sortable:false}, 
                    {name:'id',index:'id',width:55,resizable:true, hidden: true, editable:false,editoptions:{readonly:true,size:10}},
                    {name:'date',index:'date',width:120, resizable:true, sorttype:"date", editable:true,editoptions:{size:20}},
                    {name:'title',index:'title',width:400,resizable:true, editable:true,editoptions:{size:50}},
                    {name:'text',index:'text',width:120, hidden:true, resizable:true, editable: true,edittype:"textarea", editoptions:{rows:"2",cols:"20"}},
                   ],
        pager: jQuery('#pager1'),
        rowNum:10,
        rowList:[1, 5,10,20,30],
        viewrecords: true,
        multiselect: false,
        sortname: 'Date',
        sortorder: "desc",
        imgpath: '<%=ResolveUrl("~//Content/jqgrid/themes/basic/images") %>',
        caption: 'Announcements',
        editurl: '<%=Html.BuildUrlFromExpression<AnnouncementController>(c => c.Edit())%>'
      }).navGrid('#pager1',                                                     // Pager div
            {add: false, edit:true, del:false, search: false},                  // Options
            {height: 280, width: 500, reloadAfterSubmit: false,                 // Edit Options
                onInitializeForm : function(formid) {
                    jQuery("#date",formid).datepicker({showOn: 'focus'});
                }
            },
            {},                                                                 // Add options
            {}                                                                  // Delete Options
            );
    });

Thoughts?