如何在jquery中调用.load函数时在url动作中传递参数

Question

我有下面的代码 但它在当前上下文中不存在给出错误param1

   $('#dialog').dialog({

                autoOpen: true,
                width: 400,
                resizable: false,
                title: 'My Table',
                modal: true,
                open: function (event, ui) {
                 var param1 = $('#txtfirst').val();
                 var param2 = $('#txtlast').val();
                url = "@(Html.Raw(Url.Action("Index1", new { first = param1, last = param2 })))";
                alert(url);
                 $(this).load(url);
///////////////////////////
<div id="dialog"></div> 
<input id="txtfirst" type="text"/>
<input id="txtlast" type="text"/>      
<input type="button" value="Get Form" onclick="getForm()" />