public boolean isNumber(String s) {
    	s = s.trim();
    	if (s == null || s.length() == 0)
    		return false;

    	String s1[] = s.split("e");
    	if (s1.length > 2 || s1.length == 0)
    		return false;
    	
    	for (String str : s1)
    		if (isValid(str) == false)
    			return false;
    	
    	return true;
    }