<!-- // invisibility mode on

// email
function checkEmail() {
  var arg=checkEmail.arguments;
  var str=arg[0];
  var vnm=(arg.length>1)?arg[1]:"email address";
  var err="";
  var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/; 
  var emailFilter=/^.+@.+\..{2,3}$/;

  if(str=="") err="You didn't enter an "+vnm+".\n";
  if(!(emailFilter.test(str))) { 
     err="Please enter a valid "+vnm+".\n";
  } else {
    //test email for illegal characters
    if (str.match(illegalChars)) err="The "+vnm+" contains illegal characters.\n";
  }
  return err;    
}


// phone number - strip out delimiters and check for 10 digits
function checkPhone() {
  var arg=checkPhone.arguments;
  var str=arg[0];
  var vnm=(arg.length>1)?arg[1]:"phone number";
  var err="";
  
  if(str=="") err="You didn't enter a "+vnm+".\n";

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


// password - between 6-8 chars, uppercase, lowercase, and numeral
function checkPassword () {
  var arg=checkPassword.arguments;
  var str=arg[0];
  var vnm=(arg.length>1)?arg[1]:"password";
  var err="";
  var illegalChars= /[\W_]/; // allow only letters and numbers

  if (str.trim() == "") err="You didn't enter a "+vnm+".\n";
  if (illegalChars.test(str)) err="The "+vnm+" contains illegal characters.\n";
  
  return err;    
}    


// password - between 6-8 chars, uppercase, lowercase, and numeral
function checkPasswordEqual () 
{
  	var arg=checkPasswordEqual.arguments;
	var err="";
  	if(arg[0] != arg[1])
		err="Your passwords do not match.\n";
	
  	return err;    
} 


// username - 4-10 chars, uc, lc, and underscore only.
function checkUsername (strng) {
  var arg=checkUsername.arguments;
  var str=arg[0];
  var vnm=(arg.length>1)?arg[1]:"username";
  var err="";
  var illegalChars= /\W/; // allow letters, numbers, and underscores

  if(str=="") err="You didn't enter a "+vnm+".\n";
  if (illegalChars.test(str)) err="The "+vnm+" contains illegal characters.\n";

  return err;
}       


// non-empty textbox
function isEmpty(str) {
  var arg=isEmpty.arguments;
  var str=arg[0];
  var vnm=(arg.length>1)?arg[1]:"mandatory text field";

  var err="";
  
  if(str.length==0) err="The "+vnm+" has not been filled in.\n";
  return err;	  
}


// -->