Usually when I write text in firefox on Windows, I can change the text alignment by clicking on Left Shift + Left Ctrl.
In suse, it doesn’t work.
Which setting I need to change in order to control the text alignment?
Thanks! 
You don’t say which desktop you are using; if it is KDE, try System Settings>Keyboard and mouse
sorry, yes I’m using KDE. Tried to go there but didn’t find any option that changes the text alignment. The only text-relevant option that I found was changing the language, which I already did via:
Configure Desktop -> Regional & Language -> Keyboard Layout -> Advanced
As you can see in the image here.
Could it be because of my keyboard?
My keyboard: Microsoft Multimedia Keyboard 1.0A
I can see that the closest supported keyboard is: Microsoft Wireless Multimedia Keyboard 1.0A (as seen in Keyboard Layout)
I have SuSE 11.2 64bit
There are no global shortcut keys for alignment in openSUSE (or any other linux I’m aware of). When you say alignment do you mean centered, left justified, or right justified? If so, that is done on an individual program basis in linux. Therefore, try going to a firefox (mozilla) forum for a solution.
If that’s not what you mean by alignment, then you need to be more specific please.
Yes, but usually it’s only need to be right or left justified (there’s no center, usually).
That’s because I need to write from left to right and from right to left. (depends on the language)
Thus it is difficult to write in English where a text field is configured to be right aligned (text located on the right side of the text field, instead of the left side as it should be).
In Firefox, I have the “Switch Text Direction” which isn’t convenient, so I prefer to use a keyboard shortcut like Ctrl + Shift (as in Windows).
In KWrite, I found the “Align” option under the Tools label, but it doesn’t work.
The text alignment is a very important feature for me, and I must have the option to change the text alignment. I appreciate your help!