not getting the output

[beginner2011]

Hi, can u please help me understand why i'm not geting the proper output.
I tried implementing a code from a text book for reverse polish calculator.
In reverse polish notaion each operator follows it operands.
Example, if i want to calculate
(1-2)*(4+5)
in reverse polish notation it is written as
1 2 - 4 5 + *

if i give the above input "switch statement takes the default case and prints invalid option". below is the code .

#include<stdio.h>
#include<stdlib.h>

#define MAXOP 100 /* max size of operand or operator */
#define NUMBER 0 /* signal that number was found */

int getop(char s[]);
void push(double );
double pop();

void main()
{
int type;
double op2;
char s[MAXOP];

while((type=getop(s))!=EOF)
{
switch(type)
{
case NUMBER:
push(atof(s));
break;
case '+':
push(pop()+pop());
break;
case '*':
push(pop()*pop());
break;
case '-':
op2=pop();
push(pop()-op2);
break;
case '/':
op2=pop();
if(op2!=0)
push(pop()/op2);
else
printf("error:division by zero\n");
break;
default:
printf("invalid option\n");
break;
}
}
}

#define MAXVAL 100 /* max depth of val stack */
int sp=0; /* next free stack position */
double val[MAXVAL]; /* value stack */

void push(double f)
{
if(sp<MAXVAL)
val[sp++]=f;
else
printf("stackfull,can't push %g\n",f);
}

double pop()
{
if(sp>0)
return val[--sp];
else
{
printf("stack empty\n");
return 0.0;
}
}

#include <ctype.h>

int getch();
void ungetch(int);

/*getop: get next operator or operand */
int getop(char s[])
{
int i,c;
while ((s[0]=c=getch()) == ' '||c=='\t');
s[1]='\0';
if(!isdigit(c) &&c!='.')
return c; /* not a number */
i=0;
if(isdigit(c)) /* collect integer part */
while(isdigit(s[++i]=c=getch()));
if(c=='.') /* collect fraction part*/
while(isdigit(s[++i]=c=getch()));
s[i]='\0';
if(c!=EOF)
ungetch(c);
return NUMBER;
}

#define BUFSIZE 100

char buf[BUFSIZE]; /*buffer for ungetch */
int bufp=0; /* next free position in buf */

int getch() /* get a (possibly pushed back ) character */
{
return (bufp>0)?buf[--bufp]:getchar();
}

void ungetch(int c) /* push character back on input */
{
if(bufp>=BUFSIZE)
printf("too much chars\n");
else
buf[bufp++] = c;
}

[Observer]

case '\n':
    printf("result = %lf\n", pop());
    break;

[beginner2011]

Thanks Observer.. i made a silly mistake by not giving '\n ' option in case statement.. my bad.. thanks for your reply .. works fine now