var COST_OF_SHIRTS;
var stock = readInt("How many t-shirts do we have in stock");

function start(){
    while(stock>0){
        println("we have "+stock+ " number of tshirts in inventory");
        var numtobuy=readInt("how many tshirts would you like to buy");
        println("you will pay $"+numtobuy*COST_OF_SHIRTS);
        if(numtobuy<=stock){
            stock=stock-numtobuy;
            println("now we have "+stock+"tshirts");
        }else{
            println("sorry. there is not enough tshirts in stock for you to purchase.");

        }

    }
    println("we are all out of tshirts. we need to order more");
}