postfix calculator

[mrbains]

i am trying a postfis calculator so far i wrote

#include<stdio.h>
#include<string.h>

int st[15],top=0;
void push(int);
int pop(void);
void print(); 

main()
{int ch;
 char o;
 char st[15],temp[15][5];
 float arr[15];
 int i=0,j=0,r=0,c=0,l=0,t;
 printf("\nEnter Expression");
 fgets(st,15,stdin);

 printf("\nEX=%s",st);
 l=strlen(st);

 while(i<l)
 { one:  if(st[i]=='+' || st[i]=='-' || st[i]=='*' || st[i]=='/')
      {o=st[i];
	switch(o)        
	{case '+': t=pop();printf("\nadding %d pushing ",t);
              push(pop()+t);
  		i++;goto one;//break;
        case '-': t=pop();
 	      push(t-pop());	
            	break;
        case '*':t=pop();
             push(t*pop());
  		break;
        case '/':t=pop();
	     //pop();
             push(pop()/t);
        default:break;
              }
              }
else
 
             while(st[i]!='\0' && st[i]!=' ')
  		 { 
  		   temp[r][c]=st[i];
 
  		   i++;
  		   c++;

  		 }temp[r][c]='\0';
  		  printf("\npushing %d",atoi(temp[r]));
		  
		  push(atoi(temp[r]));
  		  r++;
  		  i++;c=0;
  		
	
		
        
       }

    


print();
}



void push(int i)
{puts("\ninpush");
 if(top==15)
  {printf("\nStack full");
   return;
   }
   
   st[top]=i;
   printf("\nst=%d,top=%d",st[top],top);
   top++;

}

int pop()
{ if(top==-1)
  { printf("\nUnder");}
//print("\npop=%d",st[top]);
return(st[--top]);

}

void print()
{ 
top--;
printf("\n\n\nResult=%d\n\n",st[top]);

}

iam not getting the right result though in out out ican see the result getting pushed in stack but the it pushes 0 and result is 0.
what else can i do??
Thnx.

[Bayint Naung]

I think it's better to write separate function for parsing. K&R book has example postfix calculator.
And fix your indentation.It's hard to read your code. http://www.csd.uoc.gr/~hy150b/spring...ple/index.html
I hope you learn something from it...