how to change the indentation style of emacs

[Anand Dhanakshirur <adhanakshirur@yahoo.com>]

Hi,
I am using emacs for c and c++ files.

1. Presently(default), In a C program,
after "for" loop, the next line(the next line starting with
"{" is indented(shifted) by 2 spaces.
I want to change this.
I want the next line is not shifted by 2 spaces when i press TAB key.(for indentation)
basically
Now it is, for (i=0;i<10; i++)
             {
             }

I want this to be changed as 
           for (i=0; i<10;i++)

2 .One more thing want to do.
after opening for loop of if condition,
the next line is getting shiftedby 2 spaces.
I want the next line to be shifted by 4 spaces.

How to do these 2 things?