请问如何实现IP地址框

Question

look
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<style>
.ipSection{
border:none;
width:21px;
}
</style>
<input type="hidden" name="ip" id="ip" value="0.0.0.0"><input type="button" onclick="alert(document.all.ip.value);"  value="showIp">
<div style="border:1px solid #888;width:110px;">
<input type="text" name="ipSection">.<input type="text" name="ipSection">.<input type="text" name="ipSection">.<input type="text" name="ipSection">
</div>
<script language="javascript">
var ip = document.getElementsByName("ipSection");
for(var i=0;i<ip.length;i++){
ip[i].className="ipSection";
ip[i].maxLength=3;
ip[i].value=0;
ip[i].index=i;
ip[i].onfocus=function(){this.select();}
ip[i].onkeydown=function(){
if(!(event.keyCode>=48 && event.keyCode<=57) && !(event.keyCode>=96 && event.keyCode<=105))event.returnValue=false;
}
ip[i].onkeyup=function(){
document.all.ip.value=ip[0].value+"."+ip[1].value+"."+ip[2].value+"."+ip[3].value;
if(this.value.length==3 && event.keyCode!=8 && event.keyCode!=46 && !(event.keyCode>=37 && event.keyCode<=40)){
if(this.index==3)return;
document.getElementsByName("ipSection")[this.index+1].focus();
// alert(event.keyCode);
}
}
ip[i].onblur=function(){
if(this.value*1>255)this.value=255;
}
}
</script>

Answer 1

<style>
div.IPDiv{background:#ffffff;width:120;font-size:9pt;text-align:center;border:2 ridge threedshadow;border-right:inset threedhighlight;border-bottom:inset threedhighlight;
}
input.IPInput{width:24;font-size:9pt;text-align:center;border-width:0;
}
</style>
<script language="JScript" for="document" event="onkeydown">
if(event.keyCode==13)event.keyCode=9;
</script>
<script language="JScript">
var IPlikeInputStr=[];
for(var i=0;i<4;i++)IPlikeInputStr[i]="<input class=IPInput name=IPInput type=text size=3 maxlength=3 onkeydown='if(event.srcElement.value.length==3||event.keyCode==39)event.keyCode=9'>"+(i==3?"":".");
document.write("<div class=IPDiv>"+IPlikeInputStr.join("")+"</div>");
</script>
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