function validateContact() {
    
    valid_email_reg =  /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

    if (document.contactform.name.value == 'Name' || document.contactform.name.value == '') {
        alert('Please enter your name.');
    } else if (document.contactform.surname.value == 'Surname' || document.contactform.surname.value == '') {
        alert('Please enter your surname.');
    } else if (document.contactform.number.value == 'Number' || document.contactform.number.value == '') {
        alert('Please enter your number.');
    } else if (valid_email_reg.test(document.contactform.email.value) == false) {
        alert('Please enter a valid email address.');
    } else if (document.contactform.location.value == 'Location' || document.contactform.location.value == '') {
        alert('Please enter your location.');

    } else if (document.contactform.comments.value == 'Comments' || document.contactform.comments.value == '') {
        alert('Please enter your comments.');
    } else {
        document.contactform.submit();
    }
}