如何乘用javascript，並將結果輸出到另一個文本字段兩個文本字段

Question

我使用這個代碼

<script type="text/javascript"> 
    $(function() { 
     $("#addAll2").click(function() { 
      var add = 0; 
      $("#discount") = $dis 
      $(".amt2").each(function() { 
       add += document.getElementById('subtotal').value * document.getElementById('discount').value/100; 
      }); 
      $("#discountamt").val(add.toFixed(2)); 
     }); 
    }); 
</script> 
<script type="text/javascript"> 
    $(function() { 
     $("#addAll").click(function() { 
      var add = 0; 
      $(".amt").each(function() { 
       add += Number($(this).val()); 
      }); 
      $("#subtotal").val(add.toFixed(2)); 
     }); 
    }); 
</script> 
<script type="text/javascript"> 
    $(function() { 
     $("#addAll3").click(function() { 
      var add = 0; 
      $(".amt3").each(function() { 
       add += Number($(this).val()); 
      }); 
      $("#sum").val(add.toFixed(2)); 
     }); 
    }); 
</script> 

隨着這些領域：

<fieldset> 
    <legend>Items</legend> 
    <table> 
    <thead> 
     <tr> 
     <th scope="col" width="100px">ALU</th> 
     <th scope="col" width="400px">Item Name</th> 
     <th scope="col" width="100px">Item Price</th> 
     </tr> 
    </thead> 
    <tbody> 
     <tr> 
     <td><input name="alu1" id="alu1" type="text" size="15" /></td> 
     <td><input name="itemname1" id="itemname1" type="text" size="75" /></td> 
     <td>$ 
      <input name="price1" id="price1" class="currency amt amt1" type="text" size="14" value="0.00" /></td> 
     </tr> 
    </tbody> 
    </table> 
    <button>Add Row</button> 
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> 
    <script> 
    $(document).ready(function($) 
    { 
     // trigger event when button is clicked 
     $("button").click(function() 
     { 
      // add new row to table using addTableRow function 
      addTableRow($("table")); 
      // prevent button redirecting to new page 
      return false; 
     }); 

     // function to add a new row to a table by cloning the last row and 
     // incrementing the name and id values by 1 to make them unique 
     function addTableRow(table) 
     { 
      // clone the last row in the table 
      var $tr = $(table).find("tbody tr:last").clone(); 
      // get the name attribute for the input and select fields 
      $tr.find("input,select").attr("name", function() 
      { 
       // break the field name and it's number into two parts 
       var parts = this.id.match(/(\D+)(\d+)$/); 
       // create a unique name for the new field by incrementing 
       // the number for the previous field by 1 
       return parts[1] + ++parts[2]; 
      // repeat for id attributes 
      }).attr("id", function(){ 
       var parts = this.id.match(/(\D+)(\d+)$/); 
       return parts[1] + ++parts[2]; 
      }); 
      // append the new row to the table 
      $(table).find("tbody tr:last").after($tr); 
     }; 
    }); 
    </script> 
<div class="fieldline" style="text-align:right;"> 
    <input id="addAll" type="button" value="Calculate Subtotal" /> 
    <label>Subtotal: $ 
    <input size="18" name="subtotal" id="subtotal" class="amt2 amt3" type="text" value="0.00" /> 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <label>Discount: 
    <input size="18" name="discount" id="discount" type="text" value="00" />% 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <input id="addAll2" type="button" value="Calculate Discount" /> 
    <label>Discount Amount: $ 
    <input size="18" name="discountamt" id="discountamt" class="amt3" type="text" value="0.00" /> 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <label>Shipping Method: 
     <select name="shipmeth" id="shipmeth" onchange="MM_jumpMenu('parent',this,0)"> 
     <option></option> 
     <option value="freeups">FREE UPS Ground</option> 
     <option value="upsground">UPS Ground</option> 
     <option value="ups2">UPS 2nd Day</option> 
     <option value="ups3">UPS 3rd Day</option> 
     <option value="ups1">UPS Next Day Air</option> 
     <option value="upscanada">UPS Canada</option> 
     <option value="uspsint">USPS International</option> 
     <option value="dhlint">DHL International</option> 
     <option value="freeship">Free Shipping Override</option> 
     </select> 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <label>Shipping Cost: $ 
     <input size="18" name="shipcost" id="shipcost" class="amt3" type="text" value="0.00" /> 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <input id="addAll1" type="button" value="Calculate CA TAX" /> 
    <label>Sales Tax: $ 
     <input name="salestax" type="text" id="salestax" class="amt3" size="18" value="0.00" /> 
    </label> 
    </div> 
    <div class="fieldline" style="text-align:right;"> 
    <input id="addAll" type="button" value="Calculate Total" /> 
    <label>Total: 
     <input size="18" required="required" name="sum" id="sum" type="text" value="0.00" /> 
    </label> 
    </div> 
</fieldset> 

我有它，所以它calulates的小計，並將其放入。但是，當我嘗試允許它將折扣字段乘以折扣並將其乘以100後，將折扣Ammount字段中的結果除以100。它似乎沒有工作。我也嘗試過不同的變化。

如果我能得到折扣，我應該可以計算剩餘的總額字段。

謝謝！

Answer 1

線

$("#discount") = $dis 

不看我的權利 - 嘗試刪除它。我在這個JSFiddle中評論過它，它似乎是做你想做的。