Webfrom Validation on textfiled when using default value I am having a problem where I need to use the default value of a text field to initially populate the from visually. Unfortunately after doing this the field validates as if it has been filled out by a user.
I am attempting to do a custom validation function to check against the default value of the field. So if the field has its default value to still validate as a mandatory field normally would.

The following is my attempt to do this. Am I going in the right direction?

    function MY_MODULE_form_alter(&amp;$form, $form_state, $form_id) {

    if ($form_id == 'webform_client_form_6'){
       //kpr($form);    
        $form['#validate'][] = 'MY_MODULE_validate_form';
    }


}

function MY_MODULE_validate_form($form,&amp;$form_state){
if ($form_state['submitted']['full_name']['#default_value'] == "Full Name") {
    form_set_error('full_name', t('You Must enter your full name'));
    }

}


Any help is much appreciated.
Sorry that this isnt a direct answer to your question, but it seems to me to be bad practice to use a default value in an input field and then disregard it as a submission. Would a placeholder not  be more appropriate for your requirements? 
You could even style the placeholder to look like form input via CSS