如何在$ .ajax（）error（）上显示BlockUI模态对话框？

startValidateFormParameters()

url

error()

alert()

$(document).ready(function() {
    ...
    $(\'#modalErrorOK\').click(function() { 
        $.unblockUI(); 
        return false; 
    }); 
});

function startValidateFormParameters() {
    $.blockUI({
        message: \'<h1><span style=\"display:inline-block; vertical-align:middle\"><img src=\"https://example.com/resources/indicator.gif\"/></span>\\
 Validating form parameters...</h1>\'
    });
    validateFormParameters();
}

function validateFormParameters() {
    $.ajax({
        url: \"/validateFormParameters.pl\",
        type: \"POST\",
        data: ({\"formSummary\" : JSON.stringify($.foobar.formSummary)}),
        dataType: \"JSON\",
        cache: false,
        success: function (response){
            alert(JSON.stringify(response));
        },
        error: function (request, status, error) {
            if (request.status == 401) { 
                window.location.replace(document.location.href);
            }
            else if (request.status == 403) {
                $(\'#modalErrorMsg\').replaceWith(\'<div id=\"modalErrorMsg\">\' + request.responseText + \'</div>\');
                $.blockUI({
                    message: $(\'#modalError\')
                });
            }
            else
                alert(request.status + \"\\n\" + request.responseText);
        }
    });
}

$(document).ajaxStop($.unblockUI);

<div id=\"modalError\" style=\"display:none; cursor: default\">
    <h1>Error</h1>
    <div id=\"modalErrorMsg\"></div>
    <input type=\"button\" id=\"modalErrorOK\" value=\"OK\" />
</div>