// Copyright © 2001 by Apple Computer, Inc., All Rights Reserved.
//
// You may incorporate this Apple sample code into your own code
// without restriction. This Apple sample code has been provided "AS IS"
// and the responsibility for its operation is yours. You may redistribute
// this code, but you are not permitted to redistribute it as
// "Apple sample code" after having made changes.

// email

function checkEmail (strng) {
var error="";
if (strng == "") {
   error = "You didn't enter an email address.\n";
}

    var emailFilter=/^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.\n";
    }
    else {
//test email for illegal characters
       var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
         if (strng.match(illegalChars)) {
          error = "The email address contains illegal characters.\n";
       }
    }
return error;    
}


// phone number - strip out delimiters and check for 10 digits

function checkPhone (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a phone number.\n";
   return error;
}

var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); //strip out acceptable non-numeric characters
    if (isNaN(parseInt(stripped))) {
       error = "The phone number contains illegal characters.\n";
  
    }
    if (!(stripped.length == 10)) {
	error = "The phone number is the wrong length. Make sure you included an area code.\n";
    } 
return error;
}
function checkZip (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a zip code.\n";
}
    if (isNaN(parseInt(strng))) {
       error = "The zip code contains illegal characters.\n";
  
    }
    if (!(strng.length == 5)) {
	error = "The zip code is the wrong length.\n";
    } 
return error;
}
function checkExp (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter an expiration date.\n";
   return error;
}

var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); //strip out acceptable non-numeric characters
    if (isNaN(parseInt(stripped))) {
       error = "The expiration date contains illegal characters.\n";
  
    }
return error;
}
function checkSecurity (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a security code.\n";
   return error;
}

    if (isNaN(parseInt(strng))) {
       error = "The securuty code contains illegal characters.\n";
  
    }
    if ((strng.length > 4)||(strng.length < 3)) {
	error = "The The securuty is the wrong length.\n";
    } 
return error;
}


// password - between 6-8 chars, uppercase, lowercase, and numeral

function checkPassword (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a password.\n";
}

    var illegalChars = /[\W_]/; // allow only letters and numbers
    
    if ((strng.length < 6) || (strng.length > 8)) {
       error = "The password is the wrong length.\n";
    }
    else if (illegalChars.test(strng)) {
      error = "The password contains illegal characters.\n";
    } 
    else if (!((strng.search(/(a-z)+/)) && (strng.search(/(A-Z)+/)) && (strng.search(/(0-9)+/)))) {
       error = "The password must contain at least one uppercase letter, one lowercase letter, and one numeral.\n";
    }  
return error;    
}    


// username - 4-10 chars, uc, lc, and underscore only.

function checkUsername (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a username.\n";
}


    var illegalChars = /\W/; // allow letters, numbers, and underscores
    if ((strng.length < 4) || (strng.length > 10)) {
       error = "The username is the wrong length.\n";
    }
    else if (illegalChars.test(strng)) {
    error = "The username contains illegal characters.\n";
    } 
return error;
}       


// non-empty textbox

function isEmpty(strng,fld) {
var error = "";
  if (strng.length == 0) {
     error = fld+" has not been filled in.\n"
  }
return error;	  
}

// was textbox altered

function isDifferent(strng) {
var error = ""; 
  if (strng != "Can\'t touch this!") {
     error = "You altered the inviolate text area.\n";
  }
return error;
}

// exactly one radio button is chosen

function checkRadio(checkvalue) {
var error = "";
   if (!(checkvalue)) {
       error = "Please check a radio button.\n";
    }
return error;
}

// valid selector from dropdown list

function checkDropdown(choice,fld) {
var error = "";
    if (choice == 0) {
    error = "You didn't choose a "+fld+".\n";
    }    
return error;
}  

function checkType(s) {
	var c = "";
	var t = "";
	c = parseInt(s.charAt(0), 10);
	if(c==3){
		t='American Express';
	}else if(c==4){
		t='VISA';
	}else if(c==5){
		t='MasterCard';
	}else if(c==6){
		t='Discover';
	}
	return t;
}
function checkCC(s) {
	
  var error = "";
  var i, n, c, r, t;

//check for an empty string
	if (s==""){
    error = "You did not enter a credit card number.\n";
	return error;
  }
  
  
  // First, reverse the string and remove any non-numeric characters.

  r = "";
  for (i = 0; i < s.length; i++) {
    c = parseInt(s.charAt(i), 10);
    if (c >= 0 && c <= 9){
      r = c + r;
	}
  }

  // Check for a bad string.
  //check for length of the number

  if ((r.length < 13)||(r.length > 16)){
    error = "The credit card number is the wrong length.\n";
	return error;
  }

  // Now run through each single digit to create a new string. Even digits
  // are multiplied by two, odd digits are left alone.

  t = "";
  for (i = 0; i < r.length; i++) {
    c = parseInt(r.charAt(i), 10);
    if (i % 2 != 0)
      c *= 2;
    t = t + c;
  }

  // Finally, add up all the single digits in this string.

  n = 0;
  for (i = 0; i < t.length; i++) {
    c = parseInt(t.charAt(i), 10);
    n = n + c;
  }

  // If the resulting sum is an even multiple of ten (but not zero), the
  // card number is good.

  if ((n == 0) || (n % 10 != 0)) {
     error = "This is not a valid card number.\n"
  }
return error;	
}