js監聽整個頁面的回車按鈕

document.onkeydown = keyDownSearch;

function keyDownSearch(e){

    var theEvent = e.event || window.event;

    var code = theEvent.keyCode ||  theEvent.which || theEvent.charCode

    if(code == 13){

          test();

          return false;    

   }

   return true;

}

function test(){

}