// grabbed these functions from here:
// http://www.oreillynet.com/lpt/a/1142
// I figured, hey why not? not how I usually do this, but I'll give 'em a shot.

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";
	}
	
	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 (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, msg) {
	var error = "";
	  if (strng.length == 0) {
		 error = msg + "\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, msg) {
	var error = "";
		if (choice == 0) {
		error = msg + "\n";
		}    
	return error;
}