Basic Profit Calculating Program

I know that its simple math, but this streamlines the process into 4 simply entry fields. This is wrote in BASIC, not VB, just simply basic. I wrote it in a program called Just BASIC, you can try it in any other but i havent so no guarantees. This code is for anyone who wants to improve and add on. I would like fancy it up and possibly add some other features.

Code:

    nomainwin

    WindowWidth = 300
    WindowHeight = 230
    UpperLeftX = 200
    UpperLeftY = 150
    button #profit.calc, "Calculate", [calcClicked], LR, 60, 10
    textbox #profit.field1, 40, 15, 200, 25
    textbox #profit.field2, 40, 50, 200, 25
    textbox #profit.field3, 40, 85, 200, 25
    textbox #profit.field4, 40, 120, 200, 25
    open "Profit" for window as #profit

    print #profit, "trapclose [quit]"

[start]

    print #profit.field1, "Total Money"
    print #profit.field2, "Number Of Items Bought"
    print #profit.field3, "Price Bought For"
    print #profit.field4, "Price Sold For"

    wait

[calcClicked]

    print #profit.field1, "!contents? tmoney"
    print #profit.field2, "!contents? ibought"
    print #profit.field3, "!contents? pbought"
    print #profit.field4, "!contents? psold"

        let totalpaid = ibought * pbought
        let endmoney = psold * ibought
        let profit = endmoney - totalpaid
        let profitpercent = (profit / tmoney) * 100
        goto [profitNotice]

[profitNotice]

    notice "Your Profit In Gold is: "; profit
    notice "Your Percentage Of Profit is: "; profitpercent; "%"


    confirm "Calculate Another? (Y/N)?"; play$
    if instr("YESyes", play$) then goto [start]


[quit]

    close #profit

end