C program for replace character of string

SOURCE CODE:
#include<stdio.h>
#include<conio.h>
void main()
{
 int i=0;
 char str[10],och,nch;
 clrscr();
 printf("Enter a string:");
 scanf("%s",str);
 flushall();

 puts("Enter a char to be replace:");
 scanf("%c",&och);
 flushall();
 puts("Enter new character:");
 scanf("%c",&nch);
 while(str[i]!='\0')
 {
  if(str[i]==och)
  {
   str[i]=nch;
  }
  i++;
 }
 printf("new string is:");
 printf("%s",str);
 getch();
}