C Program Calculate Characters in a File

#include<stdio.h> 
 void main(int argc,char*argv[]) 
 { 
       FILE *f1; 
       char ch; 
       int character=0; 
       clrscr(); 
       if(argc!=2) 
         { 
             printf("Insufficient Arguments"); 
             exit(0); 
         } 
       f1=fopen(argv[1],"r"); 
       if(f1==NULL) 
         { 
             printf("Source Can't be Opened"); 
             exit(0); 
         } 
             ch=fgetc(f1); 
             while(ch!=EOF) 
                   { 
                        character++; 
                        ch=fgetc(f1); 
                   } 
                        fclose(f1); 
                        printf("No: of Characters are : %d",character); 
                        getch(); 
 }