<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>
<style>
#div1{position:relative;}
#div1 div{50px;height:50px;background:blue;color:#fff;font-size:20px;text-align:center;line-height:50px;position:absolute;}
</style>
<script>
window.onload = function()
{
var oTxt = document.getElementById('txt1');
var oBtn = document.getElementById('btn1');
var oDiv = document.getElementById('div1');
oBtn.onclick = function()
{
//0 0*50
//1 1*50
//2 2*50
//3 1*50
//4 0*50
//( oTxt.value + 2 );//从页面当中获取的任何数据都是一个字符串类型的 string
//alert( typeof 222 );
//
oDiv.innerHTML = '';
var num = parseInt( oTxt.value );
if( num%2==0 )
{
alert( '请输入一个奇数' );
}
else
{
for( var i=0;i<num;i++ )
{
if( i<(num-1)/2 )
{
oDiv.innerHTML +='<div style="left:'+(i*50)+'px;top:'+(i*50)+'px;">'+i+'</div>';
}
else
{
oDiv.innerHTML +='<div style="left:'+(i*50)+'px;top:'+((num-1-i)*50)+'px;">'+i+'</div>';
};
};
};
};
};
</script>
<body>
<input type="text" value="" id="txt1"> <input type="button" id="btn1" value="按钮">
<div id="div1">
</div>
</body>
</html>