& lt輸入類型=文本值= 1 onchange = " s = 1；n = parse int(this . value)；如果(n & gt0){ for(I = 1；我& lt= n；i++)s * = I；r.innerHTML=''+n+'！= '+s；} " & gt
& lt輸入類型=按鈕值= "計算" >
& ltdiv id = r & gt1!= 1 & lt；/div & gt；