Can emacs open a new line below or above the current line?

[Ronald <followait@163.com>]

Better if it can be indented automatically (for example in cc mode).

I get a habit that code the main ones first, and then add on the 
trivialities. For example:

if((n=write(fd,line,n))!=n){
	perror("write error\n");		//second
	exit(-1);				//first
}

This may also applies when I type:

a.
	if(){}
b.
	if(){
	|}		//`|' as the cursor
c.
	Then I'd like to open a line above indented automatically.
	It normally would be C-j C-p tab. Just too many key strokes.