public static String getValidDnaCharsOrN( String inString ) 
	{
		StringBuffer buff = new StringBuffer();
		
		for ( int x=0; x < inString.length(); x++ ) 
		{
			char c = inString.charAt(x);
			
			if ( c == 'A' || c == 'C' || c == 'G' || c == 'T' || 
							c == 'N' ) 
				buff.append(c);
		}
		
		return buff.toString();
	}