// 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.
//
// $Id$


// 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";
	}

	// strip out acceptable non-numeric characters
	var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); 
	
    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 (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;
}       


// url - starts with "http://"

function checkUrl (strng) 
{
	var error = "";

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

	var url = /^http:\/\//;
	
    if (!url.test(strng))
    {
		error = "Invalid URL. Valid URLs start with \"http://\".\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;
}