find all classes which are defined in directory of magento root directory that is: /js/prototype/validation.js file. Example: <input id="email_address" name="email" type="text" /> So please follow below classes which are used magento for validation. validate-no-html-tags: (HTML tags are not allowed) validate-select: (Please select an option) required-entry: (This is a required field) validate-number: (Please enter a valid number in this field) validate-number-range: (The value is not within the specified range) validate-digits: (Please use numbers only in this field. Please avoid spaces or other characters such as dots or commas) validate-digits-range: (The value is not within the specified range) validate-alpha: (Please use letters only (a-z or A-Z) in this field) validate-code: (Please use only letters (a-z), numbers (0-9) or underscore(_) in this field, first character should be a letter) validate-alphanum: (Please use only letters…