/********************************************************
 * @DESCRIPTION: validation for the format of a driver's 
 *   license list as of 2012 US Driver's Licenses formats
 * @author: Adam Bullmer
 * @date: 04/04/2013
 * 
 * @PARAM: $string, automatic input from form_validation()
 * @EXPECTED-INPUT: alpha-numeric, trimmed
 * 
 * @REQUIREMENTS: It is required to validate the DL State 
 * field FIRST in order for us to choose which regex rules
 * we will use. 
 * @FIELD: 'dl_state'
 * @FIELD-VALUE: 2 uppercase character state abbreviation
 ********************************************************/
public function dl_format($string) {
  $dlformat = array(
    'AL'=>"^[0-9]{1,7}$", //1-7Numbers
    'AK'=>"^[0-9]{1,7}$", //1-7Numbers
    'AZ'=>"(^[a-zA-Z]{1}[0-9]{8}$)|(^[a-zA-Z]{2}[0-9]{2,5}$)|(^[0-9]{9}$)", //1Alpha+1-8Numeric or 2Alpha+2-5Numeric or 9Numeric
    'AR'=>"^[0-9]{4,9}$", //4-9Numeric
    'CA'=>"^[a-zA-Z]{1}[0-9]{7}$", //1Alpha+7Numeric
    'CO'=>"(^[0-9]{9}$)|(^[a-zA-Z]{1}[0-9]{3,6}$)|(^[a-zA-Z]{2}[0-9]{2,5}$)", //9Numeric or 1Alpha+3-6Numeric or 2Alpha+2-5Numeric
    'CT'=>"^[0-9]{9}$", //9Numeric
    'DE'=>"^[0-9]{1,7}$", //1-7Numeric
    'DC'=>"(^[0-9]{7}$)|(^[0-9]{9}$)", //7Numeric or 9Numeric
    'FL'=>"^[a-zA-Z]{1}[0-9]{12}$", //1Alpha+12Numeric
    'GA'=>"^[0-9]{7,9}$", //7-9Numeric
    'HI'=>"(^[a-zA-Z]{1}[0-9]{8}$)|(^[0-9]{9}$)", //1Alpha+8Numeric or 9Numeric
    'ID'=>"(^[a-zA-Z]{2}[0-9]{6}[a-zA-Z]{1}$)|(^[0-9]{9}$)", //2Alpha+6Numeric+1Alpha or 9Numeric
    'IL'=>"^[a-zA-Z]{1}[0-9]{11,12}$", //1Alpha+11-12Numeric
    'IN'=>"(^[a-zA-Z]{1}[0-9]{9}$)|(^[0-9]{9,10}$)", //1Alpha+9Numeric or 9-10Numeric
    'IA'=>"^[0-9]{9}|([0-9]{3}[a-zA-Z]{2}[0-9]{4}$)", //9Numeric or 3Numeric+2Alpha+4Numeric
    'KS'=>"(^([a-zA-Z]{1}[0-9]{1}){2}[a-zA-Z]{1}$)|(^[a-zA-Z]{1}[0-9]{8}$)|(^[0-9]{9}$)", //1Alpha+1Numeric+1Alpha+1Numeric+1Alpha or 1Alpha+8Numeric or 9Numeric
    'KY'=>"(^[a-zA_Z]{1}[0-9]{8,9}$)|(^[0-9]{9}$)", //1Alpha+8-9Numeric or 9Numeric
    'LA'=>"^[0-9]{1,9}$", //1-9Numeric
    'ME'=>"(^[0-9]{7,8}$)|(^[0-9]{7}[a-zA-Z]{1}$)", //7-8Numeric or 7Numeric+1Alpha
    'MD'=>"^[a-zA-Z]{1}[0-9]{12}$", //1Alpha+12Numeric
    'MA'=>"(^[a-zA-Z]{1}[0-9]{8}$)|(^[0-9]{9}$)", //1Alpha+8Numeric or 9Numeric
    'MI'=>"(^[a-zA-Z]{1}[0-9]{10}$)|(^[a-zA-Z]{1}[0-9]{12}$)", //1Alpha+10Numeric or 1Alpha+12Numeric
    'MN'=>"^[a-zA-Z]{1}[0-9]{12}$", //1Alpha+12Numeric
    'MS'=>"^[0-9]{9}$", //9Numeric
    'MO'=>"(^[a-zA-Z]{1}[0-9]{5,9}$)|(^[a-zA-Z]{1}[0-9]{6}[R]{1}$)|(^[0-9]{8}[a-zA-Z]{2}$)|(^[0-9]{9}[a-zA-Z]{1}$)|(^[0-9]{9}$)", //1Alpha+5-9Numeric or 1Alpha+6Numeric+R or 8Numeric+2Alpha or 9Numeric+1Alpha or 9Numeric
    'MT'=>"(^[a-zA-Z]{1}[0-9]{8}$)|(^[0-9]{13}$)|(^[0-9]{9}$)|(^[0-9]{14}$)", //1Alpha+8Numeric or 13Numeric or 9Numeric or 14Numeric
    'NE'=>"^[0-9]{1,7}$", //1-7Numeric
    'NV'=>"(^[0-9]{9,10}$)|(^[0-9]{12}$)|(^[X]{1}[0-9]{8}$)", //9Numeric or 10Numeric or 12Numeric or X+8Numeric
    'NH'=>"^[0-9]{2}[a-zA-Z]{3}[0-9]{5}$", //2Numeric+3Alpha+5Numeric
    'NJ'=>"^[a-zA-Z]{1}[0-9]{14}$", //1Alpha+14Numeric
    'NM'=>"^[0-9]{8,9}$", //8Numeric or 9Numeric
    'NY'=>"(^[a-zA-Z]{1}[0-9]{7}$)|(^[a-zA-Z]{1}[0-9]{18}$)|(^[0-9]{8}$)|(^[0-9]{9}$)|(^[0-9]{16}$)|(^[a-zA-Z]{8}$)", //1Alpha+7Numeric or 1Alpha+18Numeric or 8Numeric or 9Numeric or 16 Numeric or 8Alpha
    'NC'=>"^[0-9]{1,12}$", //1-12Numeric
    'ND'=>"(^[a-zA-Z]{3}[0-9]{6}$)|(^[0-9]{9}$)", //3Alpha+6Numeric or 9Numeric
    'OH'=>"(^[a-zA-Z]{1}[0-9]{4,8}$)|(^[a-zA-Z]{2}[0-9]{3,7}$)|(^[0-9]{8}$)", //1Alpha+4-8Numeric or 2Alpha+3-7Numeric or 8Numeric
    'OK'=>"(^[a-zA-Z]{1}[0-9]{9}$)|(^[0-9]{9}$)", //1Alpha+9Numeric or 9Numeric
    'OR'=>"^[0-9]{1,9}$", //1-9Numeric
    'PA'=>"^[0-9]{8}$", //8Numeric
    'RI'=>"^([0-9]{7}$)|(^[a-zA-Z]{1}[0-9]{6}$)", //7Numeric or 1Alpha+6Numeric
    'SC'=>"^[0-9]{5,11}$", //5-11Numeric
    'SD'=>"(^[0-9]{6,10}$)|(^[0-9]{12}$)", //6-10Numeric or 12Numeric
    'TN'=>"^[0-9]{7,9}$", //7-9Numeric
    'TX'=>"^[0-9]{7,8}$", //7-8Numeric
    'UT'=>"^[0-9]{4,10}$", //4-10Numeric
    'VT'=>"(^[0-9]{8}$)|(^[0-9]{7}[A]$)", //8Numeric or 7Numeric+A
    'VA'=>"(^[a-zA-Z]{1}[0-9]{9,11}$)|(^[0-9]{9}$)", //1Alpha+9Numeric or 1Alpha+10Numeric or 1Alpha+11Numeric or 9Numeric
    'WA'=>"^(?=.{12}$)[a-zA-Z]{1,7}[a-zA-Z0-9\*]{4,11}$", //1-7Alpha+any combination of Alpha, Numeric, or * for a total of 12 characters
    'WV'=>"(^[0-9]{7}$)|(^[a-zA-Z]{1,2}[0-9]{5,6}$)", //7Numeric or 1-2Alpha+5-6Numeric
    'WI'=>"^[a-zA-Z]{1}[0-9]{13}$", //1Alpha+13Numeric
    'WY'=>"^[0-9]{9,10}$", //9-10Numeric
  );
	
  if (!preg_match('/'.$dlformat[$this->input->post('dlstate')].'/', $string)) {
    $this->form_validation->set_message('dl_format', 'That does not appear to be a valid Driver\'s License');
    return FALSE;
  }
  else
    return TRUE;
}