Replacing a text with other text

[newmasalaboard]

Hello,

I just wanted to ask that how can i replace a text with some other text on my forum.

For e.g. I want to replace "cat" word with "dog"

So how can i do that ??

It should be like if any one types the "cat" word in any post then it should automatically convert to "dog"

PS- "cat" n "dog" are only examples