Analog Clock in C

/*WAP to illustrate an analog clock*/
#include<graphics.h>
#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<dos.h>
#include<time.h>
#include<process.h>
#include<math.h>
void user();
float h, ma, hour, minute, sec, m, s;
void main() {
    int gdriver = DETECT, gmode, errorcode;
    struct time t;
    initgraph( & gdriver, & gmode, "C:/TC/BGI");
    errorcode = graphresult();
    if (errorcode != grOk) {
        printf("Graphics error: %s\n", grapherrormsg(errorcode));
        printf("Press any key to halt:");
        getch();
        exit(1);
    }
    loop:
        gettime( & t);
    hour = t.ti_hour;
    minute = t.ti_min;
    sec = t.ti_sec;
    if (hour > 11)
        hour = hour - 12;
    h = 90 - (hour * 30 + minute / 12);
    ma = 90 - (minute * 6);
    s = 90 - (sec * 6);
    m = minute - minute / 12;
    cleardevice();
    gotoxy(40, 15);
    printf("%2.0f:%2.0f:%2.0f", hour, minute, sec);
    gotoxy(10, 10);
    setcolor(15);
    circle(350, 250, 100);
    setfillstyle(1, 9);
    circle(350, 250, 2);
    circle(350, 250, 10);
    outtextxy(335, 200, "RADON");
    setcolor(RED);
    outtextxy(346, 160, "12");
    outtextxy(346, 340, "6");
    outtextxy(425, 247, "3");
    outtextxy(260, 247, "9");
    setcolor(7);
    line(350, 250, (350 + 70 * cos(h * 3.14 / 180)), (250 - 70 * sin(h * 3.14 / 180))); //hour hand
    setcolor(10);
    line(350, 250, (350 + 90 * cos(s * 3.14 / 180)), (250 - 95 * sin(s * 3.14 / 180))); //second hand
    setcolor(9);
    line(350, 250, (350 + 60 * cos(ma * 3.14 / 180)), (250 - 90 * sin(ma * 3.14 / 180))); //minute hand
    setcolor(8);
    if (sec > 59) {
        sec = 0;
        m++;
        m = 6;
        s = s - 90;
        if (m > 59) {
            m = 0;
            h = 6;
        }
    }
    if (!kbhit()) //check for keystroke
    {
        sec++;
        s = s - 6;
        delay(1000);
        goto loop;
    } else //when key press
    {
        getch();
        exit(0);
    }
    getch();
    closegraph();
}