To Print Stars In Different Manner

#include<stdio.h>
#include<conio.h>
void up();
void down();
void main()
{
int f;
clrscr();
printf("===::  DUSHYANT MAINWAL  ::===\n\n");

do
{
printf("\n\nEnter your opinion:\n1. Upward\n2. Downword\n3. Quit\n");
scanf("%d",&f);
switch(f)
{
case 1: up();
break;
case 2: down();
break;
case 3: break;
default: printf("Invalid Choice\n");
}
}
while(f!=3);
getch();
}
void up()
{
int n,i,j,k,s,m=1;
printf("\nEnter how many stars you want in First line\n");
scanf("%d",&n);
s=n;
for(k=1;k<=s;k++)
{
for(i=1;i<=n;i++)
{
printf(" *");
}
printf("\n");
for(j=1;j<=m && j<=s;j++)
{
printf(" ");
}
m=m++;
n=n--;
}
}
void down()
{
int n,i,j,m=1,k,s;
printf("\nEnter how many star you want in last line\n");
scanf("%d",&n);
s=n;
for(k=1;k<=s;k++)
{
for(i=1;i<=n;i++)
{
printf(" ");
}
for(j=1;j<=m && j<=s;j++)
{
printf(" *");
}
printf("\n");
n=n--;
m=m++;
}
}