function validateOnSubmit() {
    if ((document.forms.uploadForm.order_number.value==null) || (document.forms.uploadForm.order_number.value.length == 0)) {
        alert('Please enter your order number'); 
        return false;
    }
    if ((document.forms.uploadForm.userfile.value==null) || (document.forms.uploadForm.userfile.value.length == 0)) {
        alert('Please choose a file to upload'); 
        return false;
    }
    if ((document.forms.uploadForm.email.value==null) || (document.forms.uploadForm.email.value.length == 0)) {
        alert('Please enter your email address'); 
        return false;
    }
    if (document.forms.uploadForm.email.value!=document.forms.uploadForm.email2.value) {
        alert('The confirmation email address does not match. Please adjust then try again.'); 
        return false;
    }
    document.forms.uploadForm.submit();
  };