how to get if combobox selected item is null with javascript?

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Hi everyone,

I want to validate a button such that if combobox selected items count is equal to zero then button click will show an alert on client side. I am doing this:

function filterSearch()
{
  var combo = $find('<%=RadComboBox1.ClientID %>');
  var textbox = document.getElementById("txtSearch");
  var selectedItemsCount = combo.get_selectedItems().length;
  if (selectedItemsCount == 0) 
  {
    alert("You must select a category before processing search!");
    return false;
  }
}

This ain't working though. This is my button:

<asp:Button ID="btnSearch" runat="server" Style="float: left; color: black; font-weight: bold" Text="Search" OnClick="btnSearch_Click" OnClientClick="javascript: return filterSearch();" />

How can I do this?

Thanks,
Amit

Posted 8-Nov-10 19:08pm

AmitChoudhary10

Updated 8-Nov-10 20:00pm

JF2015

v3

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AmitChoudhary10 · Answer 1 · 2010-11-09T21:53:00

Here is the code i am using now,and its working fine...

C#

function filterSearch()
{
       var combo = $find('<%=RadComboBox1.ClientID %>');
       var textbox = document.getElementById("txtSearch");
       if (combo.get_selectedIndex() == null)
       {
           alert("You must select a category before processing search!!");
           return false;
       }
}

and for button same as before--

<asp:Button ID="btnSearch" runat="server" Style="float: left; color: black; font-weight: bold" Text="Search" OnClick="btnSearch_Click" OnClientClick="javascript: return filterSearch();" />

Jitendra Zaa · Answer 2 · 2010-11-09T02:31:00

Solution 1

Hi Amit,
Please look into this article.
http://shivasoft.in/view_tutorial.php?id=96[^]
I hope this would help you.

Posted 9-Nov-10 2:31am

Jitendra Zaa