title: C program crashing on scanf
body: <p>I got a simple project from university I was working on,, it was about Super Market Billing System. So I started working on but every time I give input as a user the program crashes</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  #include&lt;conio.h&gt;
  void welcome();
  void list();
  int main()
  {
  welcome();
  }
  void welcome()
  {
      int ch;
      printf("\t\t\tSuper Market\n");
      printf("Make Your choice\n");
      printf("1.Go Shopping\n2.Check Bill\n3.Check Offers");
      scanf("%d",ch);
      switch (ch)
      {
          case 1: list();
          default : printf("wrong choice");
      }
  }
  void list()
  {
      system("cls");
      printf("1.Item First");
      getch();
  }
  </code></pre>
  
  <p>What am I doing wrong?</p>