qingdi

	/**
	 * jQuery MD5 hash algorithm function
	 * 
	 * 	<code>
	 * 		Calculate the md5 hash of a String 
	 * 		String $.md5 ( String str )
	 * 	</code>
	 * 
	 * Calculates the MD5 hash of str using the » RSA Data Security, Inc. MD5 Message-Digest Algorithm, and returns that hash. 
	 * MD5 (Message-Digest algorithm 5) is a widely-used cryptographic hash function with a 128-bit hash value. MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of data. The generated hash is also non-reversable. Data cannot be retrieved from the message digest, the digest uniquely identifies the data.