GridView 选中 RadioButton 取选中一行的值

function ss()
{
    for(i=1;i<document.all.gvwjfqk.rows.length;i++) 
    { 
    var cb=document.all.gvwjfqk.rows(i).cells(0).children(0); 
    if(cb.checked) 
    {  
        temp0=document.all.gvwjfqk.rows(i).cells(1).innerText; 
      
        alert (temp0);     
    } 
   } 
 }

    <asp:GridView ID="gvwjfqk" runat="server" AutoGenerateColumns="False"
                DataKeyNames="RowGuid"   
                Width="100%">
                <Columns>
                    <asp:TemplateField HeaderText="选择">
                        <ItemTemplate> 
                         <asp:RadioButton ID="RadioButton1" runat="server" />                           
                        </ItemTemplate>
                    </asp:TemplateField>
                     <asp:BoundField HeaderText="qw" DataField="PayNum" />
                </Columns>
            </asp:GridView>            
            <asp:Button ID="Button2" runat="server" Text="Button"  OnClientClick='ss()'/>