function jsetFocus(act) {
    if (act == "name") {
        var username = document.getElementById("username");
        if (username.value == "用户名") {
            username.value = "";
        }
    }
    else {
        var password = document.getElementById("password");
        if(password.value == "密码") {
            password.value = "";
        }
    }
}
function jsetBlur(act) {
    if (act == "name") {
        var username = document.getElementById("username");
        if(username.value == "") {
            username.value = "用户名";
        }
    }
    else {
        var password = document.getElementById("password");
        if(password.value == "") {
            password.value = "密码";
        }

    }
}