function fun(arr)
{
var sum=0,ave;
for(var i=0;i<10;i++)
{
sum+=parseInt(arr[i]);
}
alert(sum);
document.getElementById('name').value=sum///////////////////
return sum;


}
document.write("<form name='mf'>");
 var a=new Array();
var b=new Array();
for(var i = 1 ; i <=10; i++){

document.write("第"+i+"个数:");
  document.write("<input type='text' id="+ i+" value="+Math.round(Math.random()*10)+"><br/>");
a[i-1]=document.getElementById(i).value;
}
document.write("平均数是：");
document.write("<input type='text' id='name' /><br/>");
document.write("<input type='button' onclick='fun(a)' value='计算平均数'>");
document.write("</form>");