c program to read a text, delete all the semicolons it has, and finally replace all ‘.’ with a ‘,’

#include <stdio.h> 
 int main() 
 { 
   char str[100], copy_str[100]; 
   char *pstr, *pcopy_str; 
   pstr = str; 
   pcopy_str = copy_str; 
   clrscr(); 
   printf (" \n Enter the string: "); 
   gets (str); 
   pstr = str; 
    while(*pstr != '\0') 
    { 
              if(*pstr != ';') 
              { 
                /* Do Nothing */ 
              } 
       if (*pstr == ';') 
       { 
        *pcopy_str = ', '; 
       } 
              else 
             { 
              *pcopy_str =*pstr; 
             } 
                  pstr++; pcopy_str++; 
    } 
      *pcopy_str ='\0'; 
      printf("\n The new text is:"); 
      pcopy_str = copy_str; 
    while(*pcopy_str != '\0') 
    { 
      printf("%c", *pcopy_str); 
      pcopy_str++; 
    } 
      return 0; 
 }