error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token

This is the main.

int
main(int argc, char *argv[]) {
    char statement[MAX_LINE];
    int statement_len;
    char type[MAX_LINE];
    char var[MAX_LINE];

    /* Print the output header comment */
    printf(OUTPUT_HEADER, argv[0]);

    /* Loop through statements read on stdin */
    while ((statement_len = next_statement(statement,MAX_LINE)) > 0) {
        printf("%s;\n",statement);
        sscanf(statement,"%s %s",type,var);
        var_lib_check(type,var);
        var_replace(statement,statement_len);
    }
    return 0;
}

This is the function where the error occurs.

void
var_replace(char statement, int statement_len){
int i;
int x;

for (i = 0; i < statement_len; i++){
    for (x = 0; x < num_of_var; x++){
        if (strcmp(var_library[x],statement[i]) == 0){
            printf("hello");
        }
    }
}
return;
}

The error:

expected '=', ',', ';', 'asm' or 'attribute' before '{' token

How do I fix this?