改成这样即可
<script type="text/javascript">
function buttonInit(){
for(var i=1;i<4;i++){
var b=document.getElementById("button"+i);
b.i = i;
b.addEventListener("click",function(){alert("Button "+ this.i);},false);
}
}
window.onload=buttonInit;
</script>
<script type="text/javascript">
function buttonInit(){
for(var i=1;i<4;i++){
var b=document.getElementById("button"+i);
b.i = i;
b.addEventListener("click",function(){alert("Button "+ this.i);},false);
}
}
window.onload=buttonInit;
</script>
<script type="text/javascript">
function buttonInit() {
for (var i = 1; i < 4; i++) {
(function (i) {
var b = document.getElementById("button" + i);
b.addEventListener("click", function () { alert("Button" + i); }, false);
})(i)
}
}
window.onload = buttonInit;
</script>