([Error] ISO C++ forbids comparison between pointer and integer)

I am new to C++ and to programming in general. I am trying to make this small code but when I want to use the if function I get this error.

I have no idea what it could be. I tried several conventions and none of them work.
I was hoping someone could give me advice on how to write this line of code better.
here is the thing

#include <iostream>
#define EXIT_SUCCESS 0
using namespace std;

int main()
{
    //variables
    char cod_ref[6];
    char des_prod[60];
    char disp;
    int size;
    int cost;
    int price;
    int num;
    //impresiones y asignación de variables
    cout<<"Digite el codigo de referencia del producto (5 digitos)" << endl;
    cin.getline(cod_ref, 6);
    cout<<"Digite la descripción del producto"<<endl;
    cin.getline(des_prod, 60);
    cout<<"Digite la talla del producto"<<endl;
    cin>>size;
    cout<<"Cantidad de productos"<<endl;
    cin>>num;
    cout<<"¿Disponible para la venta? S/N"<<endl;
    cin>>disp;
    cout<<"Digite el costo por unidad"<<endl;
    cin>>cost;
    cout<<"Digite el precio de venta por unidad"<<endl;
    cin>>price;

    //limpieza de pantalla
    system("cls");
    //impresión final
    cout<<"REFERENCIA: "<< cod_ref <<endl;
    cout<<"DESCRIPCIÓN: "<< des_prod  <<endl;
    cout<<"DISPONIBILIDAD: ";
    if( disp == "s"||"S" ){
        cout<<"Disponible";
    }else{
        cout<<"No Disponible";
    }
    cout<<"COSTO UNIDAD: "<< cost <<endl;
    cout<<"COSTO TOTAL: "<< cost * num <<endl;
    cout<<"PRECIO UNIDAD: "<< price <<endl;
    cout<<"PRECIO POR "<< num <<" UNIDADES: "<< price * num <<endl;
    cout<<"GANANCIA POR UNIDAD: "<< price - cost <<endl; 
    cout<<"GANANCIA TOTAL: " << (price * num) - (cost * num) <<endl;
    //cout<<"PORCENTAGE DE GANANCIA: "<<
    
    system("pause");
    return EXIT_SUCCESS;
}

here is where i get the error
if( disp == "s"||"S" ){

>Solution :

Use single quotes for char character comparisons, double quotes implies a string which is technically a char * type.

ie.

if (disp == 's' || disp == 'S')