Password program in C

It will take alphanumeric input and display '*' on  the screen. Backspace functionality is also there.


#include<stdio.h>
#include<conio.h>


int chk(int,int,int);
int main(void)
{  char c[20],ch;
   int i=-1,k=0,x=0,y=0;
   clrscr();
   printf("Enter Passwo:");
   x=wherex();
   y=wherey();
   do{


   ch=getch();
   if(ch=='\b')
   {
   if(chk(x,y,wherex()))
   {
   c[i]=' ';
   --i;
   }
   }
   else if(ch!='\r')
   {
       ++i;
   c[i]=ch;
   putch('*');
   }
   }while(ch!='\r');
    printf("\nPassword is:");
   while(k<=i) {
   printf("%c",c[k]);
   k++;
   }
   getch();
   return 0;
}
 int chk(int xOriginal,int yOriginal,int xCurrent)
 {
 if(xOriginal==xCurrent)
 return 0;
 gotoxy(--xCurrent,yOriginal);
  putch(' ');
  gotoxy(xCurrent,yOriginal);
  return 1;
 }