Web Browser Turbo C++ - c++

Question

So I was browsing the Internet for a project and stumbled upon this piece of code. It runs perfectly until the point you enter a website(include "www" :P) and press Enter and then boom! The program terminates, no error message, nothing.
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <graphics.h>
#include <dos.h>
#include <string.h>
void initialize_graphics_mode();
int get_key();
void draw();
union REGS i, o;
main()
{
int key, i = 0, xpos, ypos, button;
char arr[200], temp[5], *ptr;
char a[] = "C:\\Progra~1\\Mozill~1\\firefox ";
strcpy(arr,a);
i = strlen(a);
initialize_graphics_mode();
draw();
while(1)
{
if(kbhit())
key = get_key();
if((key>=97&&key<=122)||(key>=65&&key<=90)||key==46||key==47||key==63)
{
arr[i] = key;
sprintf(temp,"%c",arr[i]);
outtext(temp);
if(getx()>470)
{
clearviewport();
moveto(5,2);
}
i++;
}
else if ( key == 13 )
{
arr[i] = '\0';
system(arr);
break;
}
else if ( key == 27 )
{
closegraph();
exit(EXIT_SUCCESS);
}
if(button==1&&xpos>=150&&xpos<=480&&ypos>=300&&ypos<=330)
{
system("C:\\Progra~1\\Mozill~1\\firefox programmingsimplified.com");
break;
}
key = -1;
}
closegraph();
return 0;
}
void initialize_graphics_mode()
{
int gd = DETECT, gm, errorcode;
initgraph(&gd,&gm,"C:\\TURBOC3\\BGI");
errorcode = graphresult();
if( errorcode != grOk )
{
printf("Graphics error : %s\n",grapherrormsg(errorcode));
printf("Press any key to exit...\n");
getch();
exit(EXIT_FAILURE);
}
}
int get_key()
{
i.h.ah = 0;
int86(22,&i,&o);
return( o.h.al );
}
void draw()
{
settextstyle(SANS_SERIF_FONT,HORIZ_DIR,2);
outtextxy(275,11,"Web Browser");
outtextxy(155,451,"<a> href=http://www.programmingsimplified.com"">www.programmingsimplified.com</a>");
outtextxy(5,105,"Enter URL : ");
rectangle(120,100,600,130);
setviewport(121,101,599,129,1);
moveto(5,1);
}
Could someone help me in understanding why this happens? and possibly a fix for this?
NOTE: + It is supposed to work if you have Mozilla Firefox. If you have any other browser, please edit the code accordingly.
I am running this on Turbo C++, what would I have to do in order to convert this code for Dev-C++?
Thanks in advance.
P.S: I'm new to C++ so elaborate as much as possible.