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;    
}

function checkAucTitle(strng){
  var error = "";
  if(strng==""){
    error="You didn't enter an Auction Title. \n";
  }
  return error;
}

function checkDelivery(strng){
  var error = "";
  if(strng==""){
    error="You didn't enter a Delivery Method. \n";
  }
  return error;
}

function checkPayment(strng){
  var error = "";
  if(strng==""){
    error="You didn't enter a Payment Method. \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";
}

var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); //strip out acceptable non-numeric characters
    if (isNaN(parseInt(stripped))) {
       error = "The phone number contains illegal characters.";
  
    }
    if (!(stripped.length == 10)) {
	error = "The phone number is the wrong length. Make sure you included an area code.\n";
    } 
return error;
}


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

function checkPassword (strng1, strng2) {
var error = "";
if (strng1 == "") {
   error = "You didn't enter a password.\n";
}

    var illegalChars = /[\W_]/; // allow only letters and numbers
    
    if ((strng1.length < 5) || (strng1.length > 20)) {
       error = "The password must be 5-20 characters.\n";
    }
    else if (illegalChars.test(strng1)) {
      error = "The password contains illegal characters.\n";
    } 
    else if (!((strng1.search(/(a-z)+/)) && (strng1.search(/(A-Z)+/)) && (strng1.search(/(0-9)+/)))) {
       error = "The password must contain at least one uppercase letter, one lowercase letter, and one numeral.\n";
    }  
    if(strng1 != strng2){
      error="The passwords do not match. \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;
}       
// username - 4-10 chars, uc, lc, and underscore only.

function checkName (strng) {
var error = "";
if (strng == "") {
   error = "You need to enter a full name.\n";
}


    var illegalChars = /\W/; // allow letters, numbers, and underscores
    if ((strng.length < 1) || (strng.length > 20)) {
       error = "Sorry. Try and shorten your name.\n";
    }
    else if (illegalChars.test(strng)) {
    error = "Your name contains illegal characters.\n";
    } 
return error;
}       

// non-empty textbox

function isEmpty(strng) {
var error = "";
  if (strng.length == 0) {
     error = "The mandatory text area 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) {
var error = "";
    if (choice == 0) {
    error = "You didn't choose an option from the drop-down list.\n";
    }    
return error;
}    

function checkUserForm(theForm) {
    var why = "";
    why += checkEmail(theForm.userEmail.value);
    why += checkPassword(theForm.userPassword.value, theForm.userPasswordVerify.value);
	why += checkName(theForm.userName.value);
    if (why != "") {
       alert(why);
       return false;
    }
    
return true;
}
function checkPasswordMatch(theForm){
var why = "";
    why += checkPassword(theForm.userPassword.value, theForm.userPasswordVerify.value);
 if (why != "") {
       alert(why);
       return false;
    }
    
return true;
}