在htc函数中找不到id？急

Question

var oWindow = window;
var ele_span = oWindow.document.createElement("span");
ele_span.id="myspan";
ele_span.style.fontFamily = "Webdings";
ele_span.style.color="#ffffff"
ele_span.height=20
ele_span.style.backgroundColor="#cccccc"
ele_span.style.border="1px solid #cccccc"
ele_span.style.cursor = "hand";
ele_span.innerHTML="6";
ele_span.attachEvent("onmouseover", ButtonOver);
         spantd.appendChild(ele_span);function ButtonOver(){
var tempspan = oWindow.document.getElementById("myspan");
if(tempspan)
tempspan.style.backgroundColor='#5c5c69'
else
alert("this id is not exist")}

Answer 1

var tempspan = document.getElementByName("myspan");