How to write a comment programming in C ?

we are writing many statement in program. We understand later so we are using comment. Comment is start /* and stop */ this symbol.
/* This is a comment */.
/* This is comment.
two line*/.
.
Compiler is compiling without /* and */ ..
.
program 1 :.
.
#include     /*header file for printf() */.
#include     /*header file for clrscr() and getch() */.
.
/*this program print a massage */.
.
void main().
{.
/*clear the screens */.
clrscr().
.
/* show massage */.
.
printf("\n Hi, massage print");.
/* wait for press any key*/.
getch();.
}