var reWhitespace = /^\s+$/
var reLetter = /^[a-zA-Z]$/
var reAlphabetic = /^[a-zA-Z]+$/

var reAlphanumeric = /^[a-zA-Z0-9]+$/

var reDigit = /^\d+$/

var reLetterOrDigit = /^([a-zA-Z]|\d)$/

var reInteger = /^\d+$/

var reFloat = /^((\d+(\.\d*)?)|((\d*\.)?\d+))$/

var reDate = /^[0-9][0-9]\/[0-9][0-9]\/[0-9][0-9][0-9][0-9]$/

var reEmail = /^\w+((-\w+)|(\.\w+))*\@\w+((\.|-)\w+)*\.\w+$/

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

function isLetter (c)
{   return reLetter.test(c)
}

function isDigit (c)
{   return reDigit.test(c)
}

function isDate(d)
{
	return reDate.test(d);
}

function isEmail (s)
{
       return reEmail.test(s)
}
function reloadPage()
{
	window.location.reload(); 
}
function openWindow(theURL,winName,features) {
    window.open(theURL,winName,features);
    return false;
}
function removeLetters(field)
{
	field.value = field.value.replace(/[^0-9]/g,"");
}

function trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}
function onEnter( evt ) 
{
	var keyCode = null;

	if( evt.which ) 
		keyCode = evt.which;
	else if( evt.keyCode )
		keyCode = evt.keyCode;

	if( 13 == keyCode ) 
		return true;

	return false;
}