js里的值怎么实现既可以插入html又能作为隐藏值传递？

Javsscript 代码：

function sumPrice() { 
  var sum_all = 0; 
  var num_sum = 0; 

  for (var i = 0; i < num; i++) { 
    if(document.getElementById("deposit"+i)!=null) { 
      var sum = Math.round(document.getElementById("pprice" + i).value * 
          document.getElementById("pnum" + i).value * document.getElementById("deposit" + i).value ); 

      document.getElementById("psum" + i).innerHTML = sum; 
      num_sum += Math.round(document.getElementById("pnum" + i).value); 
      sum_all += sum; 
    }
  }

  document.getElementById("pamountsum").innerHTML = sum_all; 
  document.getElementById("pnumsum").innerHTML = num_sum; 
  document.getElementById("money").value = sum_all; 
}

HTML 代码：
<input type="hidden" name="money" value="" />
js报错说document.getElementById("money").value = sum_all;值为null或未定义