仿微博140字符限制 超过红色闪动提示js效果

var oH2 = $("#spetit_word");//提示文字
var oTextarea = $("#p_qa_content");//输入框
var oButton = $("#bt-ico");//按钮

oTextarea.live("keyup", function () {
        Limit(oTextarea, 280, oH2);
})
oButton.live("click", function () {
        if (font_count < 0 || font_count == null || font_count == 140) {
            Error(oTextarea);
        } else {          
            alert('发布成功！');
        }
});

var font_count;

function WordLength(obj) {
        var oVal = obj.val();
        var oValLength = 0;
        oVal.replace(/n*s*/, '') == '' ? oValLength = 0 : oValLength = oVal.match(/[^ -~]/g) == null ? oVal.length : oVal.length + oVal.match(/[^ -~]/g).length;
        return oValLength
}
function Error(obj) {
        var oTimer = null;
        var i = 0;
        oTimer = setInterval(function () {
            i++;
            i == 5 ? clearInterval(oTimer) : (i % 2 == 0 ? obj.css("background-color", "#ffffff") : obj.css("background-color", "#ffd4d4"));
        }, 100);
}
//obj-要检查的输入框, iNow-多少字, tit-提示框
function Limit(obj, iNow, tit) {
        var oValLength = WordLength(obj);
        font_count = Math.floor((iNow - oValLength) / 2);
        if (font_count >= 0) {
            tit.html("你还可以输入" + font_count + "字");
            return true;
        } else {
            tit.html("已超出" + Math.abs(font_count) + "字");
            return false;
        }
        return font_count;
}