asked on

How do I use the aspx page to load a JavaScript function on a button click

I need to load a JavaScript function upon a button click. I forgot how do I relate the asp control inside the aspx page with the JavaScript and the OnClick event.

Could someone please send me this?

thans,
newbieweb

ASKER CERTIFIED SOLUTION

jinn_hnnl

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jinn_hnnl

And maybe you wondered, this is how you register a javascript function which at server side you want to generate and render to your page

Hope this helps
JINN

public void Page_Load(Object sender, EventArgs e)
 {
    if(Request.QueryString["redirect"] != null)
      if(Request.QueryString["redirect"] == "true")
        if (!this.IsStartupScriptRegistered("Startup"))
        {
          // Form the script to be registered at client side.
          String scriptString = "<script language=\>";
          scriptString += "function MyFunction(){alert('hello world'}";     
          scriptString += "</script>";
          this.RegisterStartupScript("Startup", scriptString);
        }
 
       btAdd.Attributes.Add("onclick", "MyFunction()");   
 }

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jinn_hnnl

ahh, forget about line 3 and 4 (i copied it from my other solution and forget to take it off)
JINN

curiouswebster

ASKER

I was thinking more like this. Except this does not work. Is it the javaScript
of the ASP.NET that's at fault?

thanks,
newbieweb

<head runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
function DODataLookup(){
window.location = "../DataLookup.aspx";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="submitBtn" runat="server" script="DODataLookup()" Style="z-index: 100;
left: 118px; position: absolute; top: 140px" Text="Submit" />

</div>
</form>
</body>

jinn_hnnl

Oke then it should be:

<asp:Button ID="submitBtn" runat="server" OnClientClick="DODataLookup()" Style="z-index: 100; left: 118px; position: absolute; top: 140px" Text="Submit" />

Check this link
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.button.onclientclick.aspx

JINN

^^

jinn_hnnl

anyway you can set style like that for your button I guess, you will have to set the CssClass which refers to the predefine CSS class. If you want to simplify that:

<div style="z-index: 100; left: 118px; position: absolute; top: 140px">
<asp:Button ID="submitBtn" runat="server" OnClientClick="DODataLookup()" Text="Submit" />
</div>

or <span>

It is not possible to use normal html property for server control like you do with <input > <select ..> normal html element

JINN

curiouswebster

ASKER

This is not working. Could it be the path name in the JavaScript?

how do I find the error?

newbieweb

<head runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
function DODataLookup(){
window.location = "../DataLookup.aspx";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div style="z-index: 100; left: 118px; position: absolute; top: 140px">
<asp:Button ID="submitBtn" runat="server" OnClientClick="DODataLookup()" Text="Submit" />
</div>
</form>
</body>

jinn_hnnl

you can test if your button call the javascript by:

function DODataLookup(){
alert(' hey ');
window.location = "../DataLookup.aspx";
}

you see hey, then the next line is the problem, appear to me it will navigate to the parent folder of this page and lookfor datalookup.aspx ? is what you want? What you are doing is redirecting the current page to that page.

Play around with the path

Jinn

SOLUTION

Gyanendra Singh

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curiouswebster

ASKER

I'm having trouble with a null test in JavaScript for a var type:

alert('OK1');
var elem = document.getElementByID("recordLocatorTextBox");

if (elem != 'undefined')
{
alert('OK2');
}

what is the correct way to test if elem is null? I never get OK2.

newbieweb

sh0e

if(elem!=undefined)

jinn_hnnl

There are major different between undefined and null,

If you check
if (elem != null)
{
alert('OK2');
}
it's the same as
if(!elem),
and they are good enough

btw if you want to check if the property is set or not:
if (elem.style != 'undefined') is the correct way (with quote)

Keep in mind, javascript is case sensitive:
var elem = document.getElementById("recordLocatorTextBox");
(instead of ID it's Id)

JINN