function checkLogin() {
    if (document.getElementById("txtCheckCode").value == "") return false;
    if (document.getElementById("txtUserName").value == "") return false;
    if (document.getElementById("txtPassword").value == "") return false;
    document.getElementById("txtUserName").value = escape(document.getElementById("txtUserName").value);
    return true;
}

function refreshCheckCode() {
    document.getElementById("imgCheckCode").src = "/checkcode.aspx?t=" + (new Date()).getSeconds().toString();
}