// email
function checkEmail(field, message) {
	
	var error = "";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}
	
	var strng = field.value;
	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(field, message) {
	
	var error = "";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}
	
	var strng = field.value;
	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.\n";
  
	}
	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(field, message) {
	var error="";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

	var strng = field.value;
	if (strng == "") {
		error = "You didn't enter a password.\n";
	}
	var illegalChars = /[\W_]/; // allow only letters and numbers
    	if ((strng.length < 6) || (strng.length > 12)) {
		error = message+" field is the wrong length. It must between 6 and 12 characters\n";
	} else if (illegalChars.test(strng)) {
		error = message+" contains illegal characters.\n";
	} else if (!((strng.search(/(a-z)+/)) && (strng.search(/(A-Z)+/)) && (strng.search(/(0-9)+/)))) {
		error = message+" must contain at least one uppercase letter, one lowercase letter, and one numeral.\n";
	}  
	return error;    
}  

// password - between 6-8 chars, uppercase, lowercase, and numeral
function compareData(field1, field2, message) {
	var error="";
	if (field1.value == null || field2.value == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

	if (!(field1.value == field2.value)) {
		error = "The "+ message +"s are not the same\n";
	}
	return error;    
} 

// name - 4-10 chars, uc, lc, and underscore only.
function checkName(field, message) {
	
	var error="";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

	var strng = field.value;
	
	if (strng == "") {
		error = message +"\n";
	}

	/*
	NEED TO TEST FOR NUMBERS
	*/
	var illegalChars = /\W_/; // allow letters, numbers, and underscores
	if ((strng.length < 3) || (strng.length > 20)) {
		error = "The "+ message +"name is the wrong length. It must between 3 and 20 characters.\n";
	} else if (illegalChars.test(strng)) {
		error = "The "+ message +"name contains illegal characters.\n";
	} 
	return error;
}      

// username - 4-10 chars, uc, lc, and underscore only.
function checkUsername(field, message) {
	
	var error="";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

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

	var illegalChars = /\W/; // allow letters, numbers, and underscores
	if ((strng.length < 4) || (strng.length > 20)) {
		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(field, message) {
	var error = "";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

	var strng = field.value;
	
	if (strng.length == 0) {
		error = message+"\n";
	}
	return error;	  
}

// was textbox altered
function isDifferent(field, message) {
	var error="";
	if (field == null) {
		error = "Internal Error - Unable to locate the required field";
		return error;
	}

	var strng = field.value;
	
	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, message) {
	var error = "";
	if (choice == 0) {
		error = message+"\n";
   	}    
	return error;
}