Thank you both for the time it took you to write these responses.

pg I find your method interesting and agree that it is much more efficient than the one I came up with. Thanks for pointing me out a big mistake ( the number of iterations ).

jhourcle I must agree with the things you mentioned as additional problems that must be taken care of. This node was created not to accomplish some script but to seek a simillar method to the php one. The code you added along with your post is 'exactly' the anwser I was seeking, as it shows that it can be done almost exactly as in php. I tried a simillar solution by joining a list of bad words and a list of good words, but that was obviusly wrong as I did not know how to replace the word matched by the regex with the correspoding good word, you showed me that it can be done with a hash, and now I see how blind I was before. Thank you again, and thank you both for the time it took you to read this node and share your ideas.