var whitespace = " \t\n\r";

function isEmpty(s)
{
   return ((s == null) || (s.length == 0))
}
function isWhitespace (s)
{  
	var i;
	// Is s empty?
	if (isEmpty(s)) return true;

	 // Search through string's characters one by one
	 // until we find a non-whitespace character.
	 // When we do, return false; if we don't, return true.
	 for (i = 0; i < s.length; i++)
	 {   
		 // Check that current character isn't whitespace.
		 var c = s.charAt(i);
 
		 if (whitespace.indexOf(c) == -1) return false;
	 }
 
	 // All characters are whitespace.
	 return true;
}

function isEmail(string) 
{
	if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
		return true;
	else
		return false;
}