100分！gridview编辑状态下有4个文本框··要自动计算前3个文本框中float数据类型的值的积··求实现JS代码··该如何处理

<asp:TemplateField HeaderText="用量(Yid)" SortExpression="yid"> 
                            <EditItemTemplate> 
                                <asp:TextBox [color=#FF0000]ID="TextBox4" onkeydown="checkFloat(event)" runat="server" Height="22px" 
                                    Text=' <%# Bind("yid") %>' Width="50px" onkeyup="buliao(this)"> </asp:TextBox> [/color]                            </EditItemTemplate> 
                            <ItemTemplate> 
                                <asp:Label ID="Label4" runat="server" Text=' <%# Bind("yid") %>'> </asp:Label> 
                            </ItemTemplate> 
                        </asp:TemplateField> 
                        <asp:TemplateField HeaderText="单价(price)" SortExpression="price"> 
                            <EditItemTemplate> 
                                <asp:TextBox ID="TextBox5" onkeydown="checkFloat(event)" runat="server" Height="22px" 
                                    Text=' <%# Bind("price") %>' Width="50px" onkeyup="buliao(this)"> </asp:TextBox>                             </EditItemTemplate> 
                            <ItemTemplate> 
                                <asp:Label ID="Label5" runat="server" Text=' <%# Bind("price") %>'> </asp:Label> 
                            </ItemTemplate> 
                        </asp:TemplateField> 
                        <asp:TemplateField HeaderText="价格(Total)" SortExpression="total"> 
                            <EditItemTemplate> 
                                <asp:TextBox ID="TextBox6" runat="server" Height="22px" 
                                    Text=' <%# Bind("total") %>' Width="50px"> </asp:TextBox> 
                            </EditItemTemplate> 
                            <ItemTemplate> 
                                <asp:Label ID="Label6" runat="server" Text=' <%# Bind("total") %>'> </asp:Label> 
                            </ItemTemplate> 
                        </asp:TemplateField> 
                        <asp:TemplateField HeaderText="损耗(Wastage)" SortExpression="wastage"> 
                            <EditItemTemplate> 
                                <asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="True" 
                                    onselectedindexchanged="DropDownList2_SelectedIndexChanged1" onkeyup="buliao(this,this,this,TextBox6)">                                     <asp:ListItem>1.01 </asp:ListItem> 
                                    <asp:ListItem>1.02 </asp:ListItem> 
                                    <asp:ListItem>1.03 </asp:ListItem> 
                                    <asp:ListItem>1.04 </asp:ListItem> 
                                    <asp:ListItem>1.05 </asp:ListItem> 
                                    <asp:ListItem>1.06 </asp:ListItem> 
                                    <asp:ListItem>1.07 </asp:ListItem> 
                                    <asp:ListItem>1.08 </asp:ListItem> 
                                    <asp:ListItem>1.09 </asp:ListItem> 
                                    <asp:ListItem>1.10 </asp:ListItem> 
                                </asp:DropDownList> 
                            </EditItemTemplate> 
                            <ItemTemplate> 
                                <asp:Label ID="Label7" runat="server" Text=' <%# Bind("wastage") %>'> </asp:Label> 
                            </ItemTemplate> 
                        </asp:TemplateField> 
                        <asp:TemplateField HeaderText="总价(TOTAL)" SortExpression="TOTALPRICE"> 
                            <EditItemTemplate> 
                                <asp:TextBox ID="TextBox8" runat="server" Height="22px" 
                                    Text=' <%# Bind("TOTALPRICE") %>' Width="50px"> </asp:TextBox> 
                            </EditItemTemplate>

------解决方案--------------------
如果计算发生在第4个文本框获取焦点的时候：
<input id=text4 type=text onfocus="getNum(this)"/>

function getNum(layer)
{
var tr = layer.parentNode.parentNode;//获取text4所在行
var n1 = tr.childNodes[0].childNodes[0].value;
var n2 = tr.childNodes[1].childNodes[0].value;
var n3 = tr.childNodes[2].childNodes[0].value;
var n4 = parseInt(n1)*parseInt(n2)*parseInt(n3);//最好先判断一下是否为int:if(isNaN(n1))alert("非数字");
layer.value = n4;
}

------解决方案--------------------
http://blog.csdn.net/antiking/archive/2008/11/11/3278059.aspx

------解决方案--------------------

一下测试全部通过的。楼主参考一下。
里面调用的buliao方法我都把参数去掉了，用不着带参数。"损耗"那里我改成onclick事件，不是用onkeyup事件。
我加了一个文本框txtGridViewRow，用来保存编辑行索引.在触发Gridview1_RowEditing事件时给它赋值

C# code

protected void Gridview1_RowEditing(object sender, GridViewEditEventArgs e)
{
   Gridview1.EditIndex = e.NewEditIndex;
   txtGridViewRow.Text = e.NewEditIndex.ToString();
   BindGrid();
}
页面：
<asp:TextBox runat="server" ID="txtGridViewRow"></asp:TextBox>
GridView:
       <asp:TemplateField HeaderText="用量(Yid)" SortExpression="yid"> 
                    <EditItemTemplate>
                        <asp:TextBox ID="TextBox4" runat="server" Height="22px" Text=' <%# Bind("yid") %>' Width="50px" onkeyup="javascript:buliao();"> </asp:TextBox> 
                    </EditItemTemplate> 
                    <ItemTemplate> 
                        <asp:Label ID="Label4" runat="server" Text=' <%# Bind("yid") %>'> </asp:Label> 
                    </ItemTemplate> 
                </asp:TemplateField> 
                <asp:TemplateField HeaderText="单价(price)" SortExpression="price"> 
                    <EditItemTemplate> 
                        <asp:TextBox ID="TextBox5" runat="server" Height="22px" 
                            Text=' <%# Bind("price") %>' Width="50px" onkeyup="javascript:buliao();"> </asp:TextBox>
                    </EditItemTemplate> 
                    <ItemTemplate> 
                        <asp:Label ID="Label5" runat="server" Text=' <%# Bind("price") %>'> </asp:Label> 
                    </ItemTemplate> 
                </asp:TemplateField> 
                <asp:TemplateField HeaderText="价格(Total)" SortExpression="total"> 
                    <EditItemTemplate> 
                        <asp:TextBox ID="TextBox6" runat="server" Height="22px" 
                            Text=' <%# Bind("total") %>' Width="50px"> </asp:TextBox> 
                    </EditItemTemplate>
                    <ItemTemplate> 
                        <asp:Label ID="Label6" runat="server" Text=' <%# Bind("total") %>'> </asp:Label> 
                    </ItemTemplate> 
                </asp:TemplateField> 
                <asp:TemplateField HeaderText="损耗(Wastage)" SortExpression="wastage"> 
                    <EditItemTemplate> 
                        <asp:DropDownList ID="DropDownList2" runat="server" onclick="javascript:buliao();">
                            <asp:ListItem>1.01 </asp:ListItem> 
                            <asp:ListItem>1.02 </asp:ListItem> 
                            <asp:ListItem>1.03 </asp:ListItem> 
                            <asp:ListItem>1.04 </asp:ListItem> 
                            <asp:ListItem>1.05 </asp:ListItem> 
                            <asp:ListItem>1.06 </asp:ListItem> 
                            <asp:ListItem>1.07 </asp:ListItem> 
                            <asp:ListItem>1.08 </asp:ListItem> 
                            <asp:ListItem>1.09 </asp:ListItem> 
                            <asp:ListItem>1.10 </asp:ListItem> 
                        </asp:DropDownList> 
                    </EditItemTemplate> 
                    <ItemTemplate> 
                        <asp:Label ID="Label7" runat="server" Text='d'> </asp:Label> 
                    </ItemTemplate> 
                </asp:TemplateField>