js中5s内不能重复提交

<script language="javascript">
    var checkSubmitFlg = false;
    function checkSubmit() {
        if (checkSubmitFlg == true) {
            alert("正在查询中..");
            return false;
        }
        checkSubmitFlg = true;

        setTimeout(function() {
            checkSubmitFlg = false;
        }, 5000);
        return true;
    }
</script>

<form method=post action="/search.jsp#m" target="_blank"
      onsubmit="return checkSubmit();">
    <input value="小说城" type="text" name="name" size="35" maxlength="10">
    <input type="submit" id="submitInput"/>
</form>