counting the occurrence of a character in a string

 #include <stdio.h>

int occurence(char *c, char s)

{

char * ptr=c;

int count=0;

while(*ptr!='\0')

{

    if(*ptr==s)

    {

        count++;

    }

    ptr++;

}

return count;

}

int main(){

    int number;

char s='a';

char str[]="anchalaggarwal";

number=occurence(str,s);

printf("The occurence of character %c in the string is:%d",s,number);

 return 0;

}