function validateForm() {
    const phoneInput = document.getElementById('phone');
    const contactError = document.getElementById('contact-error');
    let isValid = true;

    // Clear any previous error messages
    contactError.textContent = "";

    // Validate Phone Number
    const phoneCriteria = /^\d{10}$/; // Ensure exactly 10 digits
    if (!phoneCriteria.test(phoneInput.value)) {
        contactError.textContent = "Phone number must be exactly 10 digits.";
        phoneInput.classList.add("border-red-500");  // Add red border if invalid
        isValid = false;
    } else {
        phoneInput.classList.remove("border-red-500");  // Remove red border if valid
    }

    return isValid; // Return false to prevent submission if validation fails
}