var Username = document.affLogin.elements["userid"];
Username.onfocus=function() {
    var fn = document.affLogin.elements["userid"];
    if (fn.value=="Username") fn.value="";
};
Username.onblur=function() {
    var fn = document.affLogin.elements["userid"];
    if (fn.value=="") fn.value="Username";
};

var Pass = document.affLogin.elements["password"];
Pass.onfocus=function() {
    var fn = document.affLogin.elements["password"];
    if (fn.value=="Password") fn.value="";
};
Pass.onblur=function() {
    var fn = document.affLogin.elements["password"];
    if (fn.value=="") fn.value="Password";
};