// Field-by-field validation for free_advert.php

function checkPostCode (toCheck) {

  // Permitted letters depend upon their position in the postcode.
  var alpha1 = "[abcdefghijklmnoprstuwyz]";                       // Character 1
  var alpha2 = "[abcdefghklmnopqrstuvwxy]";                       // Character 2
  var alpha3 = "[abcdefghjkstuw]";                                // Character 3
  var alpha4 = "[abehmnprvwxy]";                                  // Character 4
  var alpha5 = "[abdefghjlnpqrstuwxyz]";                          // Character 5
  

  // Array holds the regular expressions for the valid postcodes
  var pcexp = new Array ();

  // Expression for postcodes: AN NAA, ANN NAA, AAN NAA, and AANN NAA
  pcexp.push (new RegExp ("^(" + alpha1 + "{1}" + alpha2 + "?[0-9]{1,2})(\\s*)([0-9]{1}" + alpha5 + "{2})$","i"));
  
  // Expression for postcodes: ANA NAA
  pcexp.push (new RegExp ("^(" + alpha1 + "{1}[0-9]{1}" + alpha3 + "{1})(\\s*)([0-9]{1}" + alpha5 + "{2})$","i"));

  // Expression for postcodes: AANA  NAA
  pcexp.push (new RegExp ("^(" + alpha1 + "{1}" + alpha2 + "?[0-9]{1}" + alpha4 +"{1})(\\s*)([0-9]{1}" + alpha5 + "{2})$","i"));
  
  // Exception for the special postcode GIR 0AA
  pcexp.push (/^(GIR)(\s*)(0AA)$/i);
  
  // Standard BFPO numbers
  pcexp.push (/^(bfpo)(\s*)([0-9]{1,4})$/i);
  
  // c/o BFPO numbers
  pcexp.push (/^(bfpo)(\s*)(c\/o\s*[0-9]{1,3})$/i);

  // Load up the string to check
  var postCode = toCheck;

  // Assume we're not going to find a valid postcode
  var valid = false;
  
  // Check the string against the types of post codes
  for ( var i=0; i<pcexp.length; i++) {
    if (pcexp[i].test(postCode)) {
    
      // The post code is valid - split the post code into component parts
      pcexp[i].exec(postCode);
      
      // Copy it back into the original string, converting it to uppercase and
      // inserting a space between the inward and outward codes
      postCode = RegExp.$1.toUpperCase() + " " + RegExp.$3.toUpperCase();
      
      // If it is a BFPO c/o type postcode, tidy up the "c/o" part
      postCode = postCode.replace (/C\/O\s*/,"c/o ");
      
      // Load new postcode back into the form element
      valid = true;
      
      // Remember that we have found that the code is valid and break from loop
      break;
    }
  }
  
  // Return with either the reformatted valid postcode or the original invalid 
  // postcode
  if (valid) {return postCode;} else return false;
}




function form_check()
  {
  var err_msg = "Please complete the following required fields:\n\n";
  var err_flag = false;
  var err2_flag = false;
  var myPostcode;

  if (document.form1.sellers_name.value == "")
    {
    err_msg = err_msg + " - Name\n";
	err_flag = true;
	}

  if (document.form1.sellers_address.value == "")
    {
    err_msg = err_msg + " - Address\n";
	err_flag = true;
	}

  if (document.form1.sellers_postcode.value == "")
    {
    err_msg = err_msg + " - Postcode\n";
	err_flag = true;
	}

  if (document.form1.category_id.value == "")
    {
    err_msg = err_msg + " - Category\n";
	err_flag = true;
	}

  if ((document.form1.breed_id.value == "") && (document.form1.breed_freetext.value == ""))
    {
    err_msg = err_msg + " - Breed\n";
	err_flag = true;
	}


  if (document.form1.advert_title.value == "")
    {
    err_msg = err_msg + " - Advert Title\n";
	err_flag = true;
	}

  if (document.form1.advert_text.value == "")
    {
    err_msg = err_msg + " - Advert Text\n";
	err_flag = true;
	}

  if (document.form1.sellers_phone_1.value == "")
    {
    err_msg = err_msg + " - Phone 1\n";
	err_flag = true;
	}

  myPostcode = document.form1.sellers_postcode.value;
  if (document.form1.country_id.value == 1)
     // only test the format of the postcode if UK has been selected as the country
     {
     if (!checkPostCode (myPostcode))
        {
        err2_flag = true;
        }
     }
// -----------------

  if (err_flag == true)
     {
	 alert(err_msg);
	 return false;
	 } 
  else if (err2_flag == true)
     {
	 alert("The postcode you have entered is not valid");
	 return false;
	 }
  else
     {
	 return true;
	 }
   }