Display text w/out page reloading

melvik · April 6th, 2004, 11:39 PM

happy to be helpful dear friend.

Always:),
Hovik Melkomian.

sankar · April 8th, 2004, 07:49 AM

Hi there,
I tried the following file to use your technique. Perhaps I've done all wrong....

This is the file I created to test...
<%@ Page Language="VB"%>
<html>
<head>
<title>Test Dropdown list</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript">
    function DisplayValue()
    {
        var index_value;
        index_value = frm.elements['list'].selectedIndex;
        if (index_value = 1)
            alert("1");
        if (index_value = 2)
            alert("2");
    }
</script>
</head>
<body>
<form name="frm" id="frm" method="post" runat="server">
<asp:dropdownlist AutoPostBack="false" BackColor="#33FFFF" CssClass="bigdroplisttext" ForeColor="#000000" ID="list" OnSelectedIndexChanged="JavaScript:DisplayValue(); " runat="server">
    <asp:listitem Text="Name1" Value="1"></asp:listitem>
    <asp:listitem Text="Name2" Value="2"></asp:listitem>
    <asp:listitem Text="Name3" Value="3"></asp:listitem>
    <asp:listitem Text="Name4" Value="4"></asp:listitem>
</asp:dropdownlist>
</form>
</body>
</html>

It is giving me the following error:
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: BC30456: 'JavaScript' is not a member of 'ASP.Test_aspx'.

So, how do I do it then?

Quote:

quote:Originally posted by melvik
happy to be helpful dear friend.

Always:),
Hovik Melkomian.

Sankar Sengupta
Striving for the BEST

bmains · April 8th, 2004, 01:55 PM

Try:

Sub Page_Load(..)
  '"this" passes a reference to the drop down list
  DropDownList1.Attributes.Add("onchange", "DisplayValue(this);")
End Sub

Javascript:

function DisplayValue(objList) {
  var index_value = objList.selectedIndex;

  if (index_value == 1)
    alert("1");

  if (index_value == 2)
    alert("2");
}

It's been a while since I did Javascript so forgive me if it is a little "rusty."

Hope this helps.

sankar · April 12th, 2004, 01:18 AM

Hey,
Thanx a lot buddy. This is workin well. I have only one question. I want to set some value in a server side hidden field declared as:
<asp:textbox ID="emailid" Visible="false" runat="server" />
But as soon as I am trying to assign a value to this field using JavaScript like:
emailid.innerHTML = "some email address";
It says 'emailid' is undefined.
How can I store the value in a server-side hidden field control?
Thx in adv.

Quote:

quote:Originally posted by bmains
Try:

Sub Page_Load(..)
'"this" passes a reference to the drop down list
DropDownList1.Attributes.Add("onchange", "DisplayValue(this);")
End Sub

Javascript:

function DisplayValue(objList) {
var index_value = objList.selectedIndex;

if (index_value == 1)
alert("1");

if (index_value == 2)
alert("2");
}

It's been a while since I did Javascript so forgive me if it is a little "rusty."

Hope this helps.

Sankar Sengupta
Striving for the BEST

bmains · April 12th, 2004, 01:56 PM

You can only reference a field directly like that (emailid.innerHTML) in VBScript. There are several ways you can do this. I think you can do document.all('field name'). Like I said, I'm a little rusty, but you have to reference a collection field to retrieve a reference to the object. There are actually a couple of ways to reference a control, which vary by browser.

Brian

purnima · October 13th, 2004, 07:18 AM

Hi,

I tried useing the code above to put the javascript validation for dropdown.

I get a wierd error

Compiler Error Message: CS1026: ) expected
on the line where the drop down is declared, i.e. following code line.

<asp:dropdownlist AutoPostBack="false" BackColor="#33FFFF" ForeColor="#000000" ID="list" OnSelectedIndexChanged="DisplayValue();" runat="server">

I have the DisplayValue() function in the javascript block at start of page.

Please help.

bmains · October 13th, 2004, 07:33 AM

OnSelectedIndexChanged is looking for a server-side event. This statement DropDownList1.Attributes.Add("onchange", "DisplayValue(this);") actually links the dropdown to the javascript event. Remove the OnSelectedIndexChanged.

Brian

r_ganesh76 · October 13th, 2004, 07:33 AM

if you set the server side visible = false, the control will not come to the client side. in the HTML view of the page, you wont be able to see the control. You can use <input type="hidden" runat="server" id="emailid"> insted.You can use this both in the client side and the server side also.

Hope this helps..

Quote:

quote:Originally posted by sankar
Hey,
Thanx a lot buddy. This is workin well. I have only one question. I want to set some value in a server side hidden field declared as:
<asp:textbox ID="emailid" Visible="false" runat="server" />
But as soon as I am trying to assign a value to this field using JavaScript like:
emailid.innerHTML = "some email address";
It says 'emailid' is undefined.
How can I store the value in a server-side hidden field control?
Thx in adv.

Quote:

quote:Originally posted by bmains
Try:

Sub Page_Load(..)
'"this" passes a reference to the drop down list
DropDownList1.Attributes.Add("onchange", "DisplayValue(this);")
End Sub

Javascript:

function DisplayValue(objList) {
var index_value = objList.selectedIndex;

if (index_value == 1)
alert("1");

if (index_value == 2)
alert("2");
}

It's been a while since I did Javascript so forgive me if it is a little "rusty."

Hope this helps.

Sankar Sengupta
Striving for the BEST

Regards
Ganesh

r_ganesh76 · October 13th, 2004, 11:04 PM

Use a client side hidden control insted of the asp:textbox. Controls invisible at server side will not come to the client side.

I had posted this answer below. but it never came in the list

Quote:

quote:Originally posted by sankar
Hey,
Thanx a lot buddy. This is workin well. I have only one question. I want to set some value in a server side hidden field declared as:
<asp:textbox ID="emailid" Visible="false" runat="server" />
But as soon as I am trying to assign a value to this field using JavaScript like:
emailid.innerHTML = "some email address";
It says 'emailid' is undefined.
How can I store the value in a server-side hidden field control?
Thx in adv.

Quote:

quote:Originally posted by bmains
Try:

Sub Page_Load(..)
'"this" passes a reference to the drop down list
DropDownList1.Attributes.Add("onchange", "DisplayValue(this);")
End Sub

Javascript:

function DisplayValue(objList) {
var index_value = objList.selectedIndex;

if (index_value == 1)
alert("1");

if (index_value == 2)
alert("2");
}

It's been a while since I did Javascript so forgive me if it is a little "rusty."

Hope this helps.

Sankar Sengupta
Striving for the BEST

Regards
Ganesh