试图在IE8中获取表格值时变得未定义

<div class=\"login-input\">
  <input type=\"text\" name=\"userId\">
</div>

        click: function(){
            var user = document.getElementsByName(inputTitle)[0].value;
            var myRequest = new Request({
                url: \'/Context/servletName\',
                method: \'post\',
                data: {\'user\': user},
                onRequest: function(){
                    $(\'container\').setStyle(\'cursor\', \'progress\');
                },
                onSuccess: function(responseText){
                    $(\'container\').setStyle(\'cursor\', \'auto\');
                    window.location = responseText;
                },
                onFailure: function(){
                    $(\'container\').setStyle(\'cursor\', \'auto\');
                }
            });
            myRequest.send();
        }

var user = document.getElementsByName(inputTitle)[0].value;

document.getElementsByName(inputTitle)[0];

// Returns valid object
document.getElementsByName(inputTitle);

// Returns null
document.getElementsByName(inputTitle).item(0);
document.getElementsByName(inputTitle).value;