disable button until value is selected ---select---doesnt appear

Question

SO far everything working ok, button is disabled until value is selected from the drop down list, However I want ---select--- to be the first option on the drop down list, but this is not happening...any ideas as to why?

<asp:DropDownList ID="DropDownListSubContractors" runat="server" 
    AppendDataBoundItems="true" DataTextField="Company_Name" DataValueField="id" 
    onchange='selectChanged(this);'>
    <asp:ListItem Text="---Select---" Value="0" />
    <asp:ListItem Text="Option 1" Value="1" />
</asp:DropDownList>

<script type="text/javascript">

   function selectChanged(e) {
    document.getElementById("<%= addNewSubContractor.ClientID %>").disabled 
      = (e.options[e.selectedIndex].value == "0") ? "disabled" : "";
                          }
</script>

<asp:Button ID="addNewSubContractor" Text="Add Sub Contractor" 
    OnClick="UploadSubContractor" runat="server" disabled='disabled' />

I don't know about asp, but in HTML, there's the 'selected'-tag, which makes the corresponding entry the 'selected' one. — Refugnic Eternium, Feb 10 '13 at 13:25

score 1 · Accepted Answer · answered Feb 10 '13 at 14:12

Showing the manually added items first followed by the data bound items is the default behavior of the drop down list, so ---Select--- should in theory be the first item.

I suspect there is some logic elsewhere(can be javascript or code behind) which sets the selected item to something else i.e:

DropDownListSubContractors.SelectedIndex = 1;

Have a good look through your code and make sure the selected item is not being re-set anywhere

score 0 · Answer 2 · answered Feb 10 '13 at 15:57

0

Have you got append databound item set to true, this checks to see if there are any items in the collection, and adds them first before binding?

answered Feb 10 '13 at 15:57

CallumHolden

83
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disable button until value is selected ---select---doesnt appear

2 Answers2