Form Validation - In Method
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index e5ef09e..a66e192 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -65,3 +65,4 @@
 $lang['form_validation_greater_than']		= 'The {field} field must contain a number greater than {param}.';
 $lang['form_validation_greater_than_equal_to']	= 'The {field} field must contain a number greater than or equal to {param}.';
 $lang['form_validation_error_message_not_set']	= 'Unable to access an error message corresponding to your field name {field}.';
+$lang['form_validation_in']		= 'The {field} field must be one of: {param}.';
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 8192245..e81216e 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1449,6 +1449,20 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Value should be within an array of values
+	 *
+	 * @param	string
+	 * @param	array
+	 * @return	bool
+	 */
+	public function in($value, $list)
+	{
+		return in_array($value, explode(',', $list), TRUE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Is a Natural number  (0,1,2,3, etc.)
 	 *
 	 * @param	string