Of course, aegis. I mean how to write laugh expression, not how to say it, i'm sorry.  

We would say "hahaha" for a normal laugh, and a "bwahaha" if we want to connote a burst out laughter or an evil laugh. :)

Thanks to all, @torusan, @aigis, @Murillo, @Tunde, @Екатерина @Mido, @Luisa.

I messaged talked to my friend several months ago, and I wrote some laugh expression, but I felt sorry that she didn't get what I write to her.

Knowing some laugh expression from other countries make me feel better

in my country is very common write: jajajaja

In Egypt we write " هههههههههههههههههههههههههههههههه" or "هاااااااااااااااااا"