问在错误消息发生后重置变量

EN

<script>
    <?php if(isset($_SESSION['error'])) { ?>
    window.setTimeout(displayErrorMessage(), 2000);

    function displayErrorMessage(){
            if(!displayErrorMessage.called) {
                    var errorMessage = ('<?php echo "ERROR: ".$_SESSION['error']; ?>');
                    // Here is where you remove the error so it won't persist to the
                    // next pages when user continues to navigate through
                    <?php if(isset($_SESSION['error'])) unset($_SESSION['error']); ?>
                    document.getElementById('errormessage').innerHTML = errorMessage;
                    resetErrorMessage();
                }

            displayErrorMessage.called = true;
        }
    <?php } ?>

    function resetErrorMessage() { 
            var errorMessage = null;
            setTimeout(function(){
                    document.getElementById('errormessage').innerHTML = "";
                }, 5000);
        }
</script>

<?php if( isset($_SESSION['error']) ) : ?>
<script>
window.setTimeout(displayErrorMessage(), 2000);

function displayErrorMessage()
{
    if(!displayErrorMessage.called)
    {
        var errorMessage = ("<?php echo "ERROR: ".$_SESSION['error'] ?>");
        document.getElementById('errormessage').innerHTML = errorMessage;
        resetErrorMessage();
    }

    displayErrorMessage.called = true;
}

function resetErrorMessage()
{ 
    var errorMessage = null;

    setTimeout(function() {
                   document.getElementById('errormessage').innerHTML = "";
               }, 5000);
}
</script>
<?php endif; ?>

<?php
unset($_SESSION['error']);
?>