C Program

[Ashishm1995]

I have got a problem with a program I just made using a C compiler.
The problem is that no matter what input I give, the answer is always 0.
Please help.
//program starts here
#include<stdio.h>
void main()
{
int line1,line2;
double pr,rate,ti,SI;
clrscr();
for(line1=0;line1<80;line1++)
{
printf("%c",'-');
}
printf("\n\t\t\tFind Simple Interest\n");
for(line2=0;line2<80;line2++)
{
printf("%c",'-');
}
printf("\nPlease enter the principle\n");
scanf("%d",pr);
printf("\nPlease enter the rate of interest\n");
scanf("%d",rate);
printf("\nPlease enter the time period\n");
scanf("%d",ti);
SI=(pr*rate*ti)/100;
printf("The simple interest is ");
printf("%d",SI);
getch();
}
//program ends here

[Bazzy]

you should pass pointers to scanf in order to get the values: scanf("%d",&pr);
http://www.cplusplus.com/reference/clibrary/cstdio/scanf/

[Ashishm1995]

I have used pointers in all scanf's.
Should I try using int.

[Duthomhas]

No, you did not use pointers. You used the double value directly -- which will cause your program to smash memory and probably segfault.

Look at the link Bazzy gave you. To read a double, you must use
- the correct conversion specifier
- a pointer to the target variable

Hence:

#include <stdio.h>

int main()
  {
  ...

  /* get loan principle, rate, and duration */
  printf( "\nPlease enter the principle\n" );
  scanf( "%lf", &pr );
  printf( "\nPlease enter the rate of interest\n" );
  scanf( "%lf", &rate );

  ...

  /* get rid of that left-over newline in the input after using scanf() */
  while (getchar() != '\n');

  /* calculate and display the interest */
  SI=(pr*rate*ti)/100.0;
  printf( "The simple interest is %f.\n", SI );

  /* keep the console window open long enough to see the program run */
  printf( "Press ENTER to continue..." );
  while (getchar() != '\n');

  return 0;
  }

Notice also that I didn't use that getch() function from <conio.h>.
The main() function returns type int.

Also, please use [code] tags.

[edit] Here's a plug for using readable variable names, also. For example, why not name the principle 'principle', instead of just 'pr'.

Hope this helps.