Multiple words str_shuffle

I am trying to scramble individual words and/or phrases. When it is a phrase I would like to keep the letters of each word together, with a space between each one. The code I have so far is below. I use PHP 4.4.7. The code below is fine for a single word; it is phrases that I am now trying to accommodate. An example: rise and shine Desired output: I S R E N A D E H I S N Thanks for your help, Ron $keyword might be $keyword = str_shuffle(strtoupper($keyword)); $buffer = ""; for ($count = 0; ($count < strlen($keyword)); $count++) $buffer .= $keyword{$count}." "; $keyword = trim($buffer); unset($buffer);