Stack using linked list code with output

Code

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

typedef struct
{
    int data;
    struct node* next;
}node;

node* top;

void create()
{
    top=NULL;
}

int isEmpty()
{
    if(top==NULL)
        return 1;
    return 0;
}

void push(int element)
{
    node* curr;

    if(isEmpty())
    {
        top = (node*)malloc(sizeof(node));
        top->data = element;
        top->next = NULL;
    }
    else
    {
        curr = (node*)malloc(sizeof(node));
        curr->data = element;
        curr->next = top;
        top = curr;
    }
}

int pop()
{
    node* curr;int element = top->data;

    if(isEmpty())
    {
        printf("Stack is empty.Can't pop");
        return -1;
    }    
    else
    {   
        curr=top->next;

        free(top);

        top=curr;

        return element;
    }
}   

void display()
{
    node* curr;

    if(isEmpty())
         printf("\nStack is empty");
    else
    {
         printf("\n");

         for(curr=top;curr!=NULL;curr=curr->next)
               printf("%d  ",curr->data);
    }
}

int main()
{
    int element;

    create();

    push(1);
    display();

    push(2);
    display();

    push(3);
    display();

    element = pop();
    if(element!=-1)printf("\nPopped element = %d",element);
    display();

    return 0;
}

O/P

1  
2  1  
3  2  1  
2  1