How can i give alphabets only validation in webform?

Question

I can give only required and maxlength validation in webform fields , How can i give

alphabets or numbers only validation in webform textfields ??

UPDATE

I used hook like this :-

function mymodule_form_alter(&$form, &$form_state, $form_id) {
    if ($form_id == 'webform_client_form_48') {
        if (!preg_match('/^[A-Za-z]+$/', $form['submitted']['name']['#value'])) {
            // $form['submitted'][$key]['#attributes']['class'] = 'error';
            form_set_error('name', t('Please enter alphabets only for Name.'));
        }
    }
}

this is working . but the order of displaying message is not proper , the first three

message is coming from ajax form validation and fourth one is from the hook , but i need

the fourth message should come first .

Answer 1

If you want to go for a module, Try the Webform Validation module

This module adds an extra tab to each webform node, allowing you to specify validation rules for your webform components. You can create one or more of the predefined validation rules, and select which webform component(s) should be validated against those. By using the hooks provided by this module, you can also define your own validation rules in your own modules.

The following validation rules are currently included:

• Numeric values (optionally specify min and/or max value)
• Minimum length
• Maximum length
• Minimum number of words
• Maximum number of words
• Equal values on multiple fields
• Unique values on multiple fields
• Specific value
• Require at least one of two fields
• Require at least one of several fields
• Minimum number of selections required
• Maximum number of selections allowed
• Exact number of selections required
• Plain text (disallow tags)
• Regular expression
• Must be empty (anti-spam: Hide with CSS)
• Words blacklist
• Must match a username