delay time and backspace

Hello everybody,

Is there a way to write a delay function that can delay what i want to display?

And Can somebody teach me how to enable this password program that if i key in the wrong input i can backspace!!
//----------------------------------------------------------------------------------
#include <stdio.h>
#include <conio.h>
#include <ctype.h>
#define pwd_size 10
int main()
{
int ch;
char pword[pwd_size];
int i = 0;

printf("Enter your password:");

while ((ch = getch()) != EOF
&& ch != '\n'
&& ch != '\r'
&& i < sizeof(pword) - 1)
{
if (isalnum(ch))
{
putchar('*');
pword[i++] = ch;

}

}

pword[i] = '\0';

printf ("\nYou entered >%s<", pword);

return 0;
}

Thank For Your help