var errorDisplayed = false;
	
	function validate(result, message, object)
	{
		if (!result)
		{
			if (!errorDisplayed)
			{
				alert(message)
				if (object) object.focus();
				errorDisplayed = true;
			}
		}
	}
	
	function allOK()
	{
		var temp = errorDisplayed;
		errorDisplayed = false;
		return !temp;
	}
	
	function isChecked(ticks)
	{		
		var ticked = false;
		for (var x=0; x < ticks.length; x++)
		{
			//if (ticks[x].checked) ticked = true;
		}
		isChecked = ticked;
	}
	
	function noInvalidChars(theField)
	{
		var newText = '';
		var theText = theField.value;
		var invalidFound = false;
		for (var x=0; x<theText.length; x++)
		{
			var code = theText.charCodeAt(x);
			if ((code >=0 && code <= 126)) newText += theText.charAt(x);
			else 
			{
				newText += '?';
				invalidFound = true;
			}
		}
		theField.value = newText;
		return !invalidFound;
	}
	
	function isEmail(testEmail)
	{
		var regex = /^[a-zA-Z0-9._-]+@([a-zA-Z0-9.-]+\.)+[a-zA-Z0-9.-]{2,4}$/;
		return regex.test(testEmail);
	}
	
	function isNumeric(text)
	{
   		var validChars = "0123456789.";
   		var isNumber = true;
   		var thisChar;

		if(text == '') isNumber = false;
 
   		for (i = 0; i < text.length && isNumber == true; i++) 
      	{ 
      		thisChar = text.charAt(i); 
      		if (validChars.indexOf(thisChar) == -1) 
        	{
         	isNumber = false;
         	}
      	}
   		return isNumber;
	}
	
function isDate(testDate)
{
	var pattern = /^(\d{1,2})(\/)(\d{1,2})(\/)(\d{2}|\d{4})$/;
	if (!pattern.test(testDate)) return false;
	
	var dateArray = testDate.split(/\//g);
	
	var day, month, year
	day = dateArray[0];
	month = dateArray[1];
	year = dateArray[2];
	
	if (month < 1 || month > 12) return false;
	if (day < 1 || day > 31) return false;
	if ((month == 4 || month == 6 || month == 9 || month == 11) && day == 31) return false;
	
    if (month == 2)
	{ // check for february 29th
        var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
        if (day > 29 || (day==29 && !isleap)) return false;
    }
	
	return true;
}