function validate(form) {
  var name = form.name.value;
  var company = form.company.value;
  var email = form.email.value;
  var telnr = form.telnr.value;
  var product = form.product.value;
  var qty = form.qty.value;
  var print_cols = form.print_cols.value;
  var date_req = form.date_req.value;
  var notes = form.notes.value;
  var emailRegex = /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/;
  
  if(name == "") {
    alert('Please enter your name.',2);
    return false;
  }
  
  if(company == "") {
    alert('Please enter the name of your organisation, or "self".',2);
    return false;
  }
  
  if(email == "") {
    alert('Please enter your email address.',2);
    return false;
  }
  if(!email.match(emailRegex)) {
    alert('You have entered an invalid email address.',2);
    return false;
  }
  if(telnr == "") {
    alert('Please enter a contact phone number.',2);
    return false;
  }
  if(product == "") {
    alert('Please enter details of your enquiry.');
    return false;
  }
  if(qty == "") {
    alert('Please enter a quantity.');
    return false;
  }
  if(print_cols == "") {
    alert('Please enter number of colours to be printed.');
    return false;
  }
  return true;
}