var regtxt = new RegExp("^([\u4E00-\uFA29]|[\uE7C7-\uE7F3]|[_]|[ ]|[a-zA-Z0-9])*$");

function validate_login() {
    var username = $('ctl00_ContentPlaceHolder1_txtUserName').value;
    var password = $('ctl00_ContentPlaceHolder1_txtPassword').value;
    //                                    if (username.leng() < 6 || username.leng() > 12) {
    //                                        alert("请输入长度6-12位用户名！");
    if (username == '' || username == null) {
        alert("请输入用户名！");
        return false;
    }
    if (password == '') {
        alert("请输入密码！");
        return false;
    }
    if (!regtxt.test(username)) {
        alert("请不要在用户名中，输入除“_”以外的特殊字符！");
        return false;
    }
    return true;

}

//String.prototype.leng = function() {
//return this.replace(/[^\x00-\xff]/g, "rr").length;
//                                }

function $(obj) {
    return document.getElementById(obj);
}