Program to calculate electricity bill of a user in different cases in C

#include <stdio.h>
#include <conio.h>
void main ()
{
char name[25];
int choice;
float cahrge1,charge2,charge3,charge4,charge5,unit1,unit2,unit3,unit4,unit5;
printf ("\n enter name of user:");
scanf ("%s", name);
printf ("\n you can perform following operation:");
printf ("\n 1. below 83.33:");
printf ("\n 2. above 83.34 to 100:");
printf ("\n 3. above 100 to 200:");
printf ("\n 4. above 200 to 300:");
printf ("\n 5. above 300:");
printf ("\n enter your choice:"):
scanf ("%d", &choice);
switch ( choice )
{
       case 1:
       printf ("\n enter value of units:");
       scanf ("%d", &unit1);
       printf ("\n Energy charge is 50:");
break;
       case 2:
       printf ("\n enter value of units:");
       scanf ("%d", &unit2);
       charge2= 0.6*unit2;
       printf ("\n Charge=%d",charge2);
break;
       case 3:
       printf ("\n enter value of units:");
       scanf ("%d", &unit3);
       charge3=( 0.8*(unit3-100)+60;
       printf ("\n Charge=%d",charge3);
break;

       case 4:

       printf ("\n enter value of units:");
       scanf ("%d", &unit4);
       charge4=( 0.9*(unit4-200)+140);
       printf ("\n Charge=%d",charge4);
break;

       case 5:

       printf ("\n enter value of units:");
       scanf ("%d", &unit5);
       charge5=( 0.9*(unit5-300)+230);
       charge5=charge5+0.15*(charge5);
       printf ("\n Charge=%d",charge5);
break;
default:
        printf ("\n Have a nice day:");
}
getch ();
}