<!-- Begin
function stringFilter (input) {
s = input.value;
filteredValues = " ";     // Characters stripped out
var i;
var returnString = "";
for (i = 0; i < s.length; i++) {  // Search through string and append to unfiltered values to returnString.
var c = s.charAt(i);
if (filteredValues.indexOf(c) == -1) returnString += c;
}
input.value = returnString;
}
function postit(){ //check postcode format is valid
 test = form.form_postcode.value; size = test.length
 test = test.toUpperCase(); //Change to uppercase
 while (test.slice(0,1) == " ") //Strip leading spaces
  {test = test.substr(1,size-1);size = test.length
  }
 while(test.slice(size-1,size)== " ") //Strip trailing spaces
  {test = test.substr(0,size-1);size = test.length
  }
 form.form_postcode.value = test; //write back to form field
 if (size < 6 || size > 8){ //Code length rule
  alert(test + " is not a valid postcode - wrong length. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
  form.form_postcode.focus();
  return false;
  }
 if (!(isNaN(test.charAt(0)))){ //leftmost character must be alpha character rule
   alert(test + " is not a valid postcode - cannot start with a number. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
  }
 if (isNaN(test.charAt(size-3))){ //first character of inward code must be numeric rule
   alert(test + " is not a valid postcode - alpha character in wrong position. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
  }
 if (!(isNaN(test.charAt(size-2)))){ //second character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
  }
 if (!(isNaN(test.charAt(size-1)))){ //third character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
  }
 if (!(test.charAt(size-4) == " ")){//space in position length-3 rule
   alert(test + " is not a valid postcode - no space or space in wrong position. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
   }
 count1 = test.indexOf(" ");count2 = test.lastIndexOf(" ");
 if (count1 != count2){//only one space rule
   alert(test + " is not a valid postcode - only one space allowed. THIS MAY NOT MATCH YOU PROPERTY CORRECTLY!");
   form.form_postcode.focus();
   return false;
  }
return true;
}
-->