function formValidator()
{
	// set up array to hold error messages
	this.errorList = new Array;

	// set up object methods
	this.isEmpty = isEmpty;	
	this.isNumber = isNumber;	
	this.isAlphabetic = isAlphabetic;	
	this.isAlphaNumeric = isAlphaNumeric;	
	this.isWithinRange = isWithinRange;	
	this.isEmailAddress = isEmailAddress;	
	this.isChecked = isChecked;	

	this.raiseError = raiseError;	
	this.numErrors = numErrors;	
	this.displayErrors = displayErrors;	
}

// check to see if input is whitespace only or empty
function isEmpty(val)
{
	if (val.match(/^s+$/) || val == "")
	{
		return true;
	}
	else
	{
		return false;
	}	
}

// check to see if input is number
function isNumber(val)
{
	if (isNaN(val))
	{
		return false;
	}
	else
	{
		return true;
	}	
}

// check to see if input is alphabetic
function isAlphabetic(val)
{
	if (val.match(/^[a-zA-Z]+$/))
	{
		return true;
	}
	else
	{
		return false;
	}	
}

// check to see if input is alphanumeric
function isAlphaNumeric(val)
{
	if (val.match(/^[a-zA-Z0-9]+$/))
	{
		return true;
	}
	else
	{
		return false;
	}	
}

// check to see if value is within range
function isWithinRange(val, min, max)
{
	if (val >= min && val <= max)
	{
		return true;
	}
	else
	{
		return false;
	}	
}

// check to see if input is a valid email address
// e-mail matching regular expression from:
// http://www.breakingpar.com/bkp/home.nsf/Doc?OpenNavigator&U=87256B280015193F87256C40004CC8C6
function isEmailAddress(val)
{
	if( val.match( /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/ ) )
	{
		return true;
	}
	else
	{
		return false;
	}	
}

// check to see if form value is checked
function isChecked(obj)
{
	if (obj.checked)
	{
		return true;
	}
	else
	{
		return false;
	}	
}


// display all errors
// iterate through error array and print each item
function displayErrors()
{
    var errMsg = "";
    
	for ( x = 0; x < this.errorList.length; x++ )
	{
	    errMsg += this.errorList[x] + '\n';
	}
	
	alert( errMsg );
}

// add an error to error list
function raiseError(msg)
{
	this.errorList[this.errorList.length] = msg;
}

// return number of errors in error array
function numErrors()
{
	return this.errorList.length;
}