删除特殊字符和限定用户输入长度

/检查非法字符并检验字符长度
function checkSpeChar(obj, byteLength, title) {
    var value = document.getElementById(obj).value;
    value = value.replace(/(^\s*)/g, "").replace(/(\s*$)/g, "");
    var ret = (/[-|;|,|\/|\(|\)|\[|\]|\}|\{|%|@|\*|!|\']/.test(value));
    var arr = ["@", "#", "$", "%", "^", "&", "*", "<", ">", "/", "\\", "\'", "'", ".", ":", "?", "[", "]", ";", "-", "、", "(", ")", "_", "\"", "~", "insert", "delete", "update", "select"];
    value = value.toLowerCase();
    for (var i = 0; i < arr.length; i++) {
        if (value.indexOf(arr[i].toLowerCase()) >= 0) {
            ret = true;
        }
    }
    if (ret == true) {
        top.LSAlert("内容中含非法字符，请重新输入！");
        document.getElementById(obj).value = '';
        return;
    }
    limitLength(value, byteLength, title, obj);
}
//验证输入字符长度
function limitLength(value, byteLength, title, attribute) {
    value = value.replace(/\r/g, "  ").replace(/\n/g, "  "); //回车换行分别替换两个空格
    var newvalue = value.replace(/[^\x00-\xff]/g, "***");
    var length = newvalue.length;
    //当填写的字节数小于设置的字节数
    if (length * 1 <= byteLength * 1) {
        return;
    }
    var limitDate = newvalue.substr(0, byteLength);
    var count = 0;
    var limitvalue = "";
    for (var i = 0; i < limitDate.length; i++) {
        var flat = limitDate.substr(i, 1);
        if (flat == "*") {
            count++;
        }
    }
    var size = 0;
    var istar = newvalue.substr(byteLength * 1 - 1, 1); //校验点是否为“×”
    //if 基点是×;
    if (count % 3 == 0) {
        size = count / 3 + (byteLength * 1 - count);
        limitvalue = value.substr(0, size);
    }
    else if (count % 3 == 1) {
        size = (count - 1) / 3 + (byteLength * 1 - count);
        limitvalue = value.substr(0, size);
    }
    else if (count % 3 == 2) {
        size = (count - 2) / 3 + (byteLength * 1 - count);
        limitvalue = value.substr(0, size);
    }
    //top.LSAlert(title + "最大输入" + byteLength + "个字节！");
    document.getElementById(attribute).value = limitvalue;
    return;
}