javascript动态文本框更改焦点

Question

我有一个HTML表单，带有一些静态文本框和一个将创建动态文本框的按钮。现在，当按钮被点击时，我希望新创建的框被聚焦。我正在使用focus（）方法，但它不起作用。另一件事是我会改变它在静态盒的工作背景颜色，但不是在动态框

function addPhone(){ 
try{ 
    var phone = document.getElementById("phone"); 
    phone.appendChild(document.createElement("Phone"+noOfPhones)); 

    var textbox = document.createElement("input"); 
    textbox.setAttribute("type", "textbox"); 
    textbox.setAttribute("id","phone"+noOfPhones); 
    textbox.setAttribute("name","phone"+noOfPhones); 

    textbox.setAttributte('onFocus','onFocus(this);'); 
    textbox.style.background="lightgrey"; 

    document.getElementById("phone").appendChild(textbox); 
    phone.appendChild(document.createElement("br")); 

    textbox.focus(); 

    noOfPhones++; 
}catch(err){ 
    alert(err); 
} 

} 

function onFocus(element){ 
element.style.background = "lightgrey"; 
} 

请帮助的onfocus（）方法。我是JS新手。由于

Answer 1

尝试：

<div id="phone"></div> 
<input type="button" onclick="addPhone()" value="Add"/> 
<script type="text/javascript"> 
var noOfPhones=0; 
function addPhone(){ 
    try{ 
     noOfPhones++; 
     var phone = document.getElementById("phone"); 
     phone.appendChild(document.createTextNode("Phone :"+noOfPhones)); 
     var textbox = document.createElement("input"); 
     textbox.setAttribute("type", "textbox"); 
     textbox.setAttribute("id","phone"+noOfPhones); 
     textbox.setAttribute("name","phone"+noOfPhones); 
     textbox.setAttribute('onfocus','onFocus(this, true);'); 
     textbox.setAttribute('onblur','onFocus(this, false);'); 
     textbox.style.background="white"; 
     document.getElementById("phone").appendChild(textbox); 
     phone.appendChild(document.createElement("br")); 
     textbox.focus(); 
    }catch(err){ 
     alert(err); 
    } 
} 

function onFocus(element, hasFocus){ 
if(hasFocus) 
    element.style.background = "lightgrey"; 
else 
    element.style.background = "white"; 
} 
</script>