function is_empty(val) {
    return (val == null || val == "");
}

function is_phone(val) {
    return val.match(/\d{3}\-\d{3}\-\d{4}/);
}    

function validate_referral_form(f) {
    if (is_empty(f.Name.value)) {
        alert("Please Enter Your Name");
        return false;
    }
    if (is_empty(f.Email.value)) {
        alert("Please Enter Your Friend's Email");
        return false;
    }
    return true;
}

function validate_login_form(f) {
    if (is_empty(f.UserName.value)) {
        alert("Please enter your username.");
        return false;
    }
    if (is_empty(f.UserPassword.value)) {
        alert("Please enter your password.");
        return false;
    }
    return true;
}

function validate_contact_form(f) {
    if (is_empty(f.AppFirstName.value)) {
        alert("Please Enter Applicant's First Name");
        return false;
    }
    if (is_empty(f.AppLastName.value)) {
        alert("Please Enter Applicant's Last Name");
        return false;
    }
    if (is_empty(f.AppEmail.value)) {
        alert("Please Enter an Email Address");
        return false;
    }
    if (!is_empty(f.AppHomePhone.value) && !is_phone(f.AppHomePhone.value)) {
        alert("Please Enter a Valid Home Phone Number");
        return false;
    }        
    return true;
}

function validate_application_form(f) {
    if (is_empty(f.AppFirstName.value)) {
        alert("Please Enter Applicant's First Name");
        return false;
    }
    if (is_empty(f.AppLastName.value)) {
        alert("Please Enter Applicant's Last Name");
        return false;
    }
    if (is_empty(f.AppEmail.value)) {
        alert("Please Enter an Email Address");
        return false;
    }
    return true;
}