為什麼我的運行後沒反映

Question

為什麼我的運行後沒反映按f12顯示index:94 Uncaught TypeError: $ is not a function     at menuFire (index:94)     at HTMLAnchorElement.onclick (index:53)

index.html92-## 96行程式碼: 

function menuFire(obj){var src = $(obj).attr('src');$('iframe').attr('src',src);}