javascript validation

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Hello everyone!
I am new to asp.net. I am working on a form containing some textboxes for userid, password and some drop down lists. I have to do some validation using java script. I have written some code as follows...

JavaScript

<script type="text/javascript">
function validate() {
if (document.getElementById("<%=txtuid.ClientID%>").value=="")
      {
      
                 alert("id Field can not be blank");
                 document.getElementById("<%=txtuid.ClientID%>").focus();
                 return false;
      }
}
</script>

XML

<body>
<form id="someID">
 <asp:textbox id="txtuid" />
<asp:button id="btn" onclientclick="return validate()" />
</form>
</body>

but the problem is that when I am placing it on a separate javascript file then its not working at all...

XML

<head>
  <script src="script/JScript.js" type="text/javascript"></script>
</head>
<body>
<form>
  <asp:button id="btnsubmit" runat="server" text="Next" width="122px" onclick="btnsubmit_Click" onclientclick="return validate()"/>
  </asp:button>
</form...>
</body>

Please help!

Posted 2-Jul-10 2:33am

i.ahmad86

Updated 2-Jul-10 3:25am

Ankur^\m/

v3

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Ankur^\m/ 2-Jul-10 9:25am

Edited for formatting and readability.

Chris Maunder 3-Jul-10 9:39am

ASP.NET validation controls emit client side validation. Did you read the article link I posted?

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Gordon Kushner · Answer 1 · 2010-07-02T02:54:00

The JavaScript file does not generate on the server, but the page does. The reason the code doesn't work is that this <%=txtuid.ClientID%>" never gets evaluated.

What you might do is make the validation script more generic and pass in the control and text to display.

In the script:

JavaScript

function validate(control, text) {
if (control.value=="")
   alert(text);

And in the page:

XML

<asp:button id="btnsubmit" runat="server" text="Next" width="122px" onclick="btnsubmit_Click" onclientclick="return validate(this, 'some message');" />

Chris Maunder · Answer 2 · 2010-07-02T15:04:00

Solution 2

Why not use the ASP.NET validation controls?

Validator Controls in ASP.NET[^]

Posted 2-Jul-10 15:04pm

Chris Maunder774.1K

Comments

i.ahmad86 3-Jul-10 0:37am

because i need only client side validations.. not on server side...

koolprasad2003 · Answer 3 · 2010-07-02T20:11:00

Use the following code

in your head tag type the following function

<script language="Javascript" type="text/javascript">
function validateME()
{
    if(document.getElementById("txtuid").value=="")
       {
          alert("Please enter user id");
          document.getElementById.focus();
          return false;
       }
}
</script>

I observed that your textbox has no runat="server" property

do the following

<body>
        <form id="frmtest">
           <asp:textbox id="txtuid" runat="server" xmlns:asp="#unknown" />
           <asp:button id="btnPressMe" onclientclick="return validateME();" runat="server" xmlns:asp="#unknown" />
        </form>
</body>

hope this helps you...:thumbsup:

Manfred Rudolf Bihy · Answer 4 · 2010-12-06T01:17:00

The following is in Validation.js file:

JavaScript

function validateME(controlID, textMessage)
{
    if(document.getElementById(controlID).value == "")
    {
          alert(textMessage);
          document.getElementById.focus();
          return false;
    }
}

In header section of html include script tag:

<script language="text/javascript" src="./pathTo/Validation.js"><script>

In your ASP.NET page do this:

ASP

<asp:button id="btnsubmit" runat="server" text="Next" width="122px" onclick="btnsubmit_Click" onclientclick="return validate()"/>

Now in your code behind file in page load somewhere do this:

C#

btnsubmit.OnClientClick = String.Format("return validateME('{0}','{1}');",btnsubmit.ClientID, "Field Xxx may not be emtpy");

By setting the OnClientClick from the behind code allows you to send all the nescessary parameters along that are needed.

If you have problems realizing this solution your welcome to ask me.

Cheers

Manfred

Blesson Mathew · Answer 5 · 2010-12-15T21:30:00

Hi,

<%=txtuid.ClientID%> which is not working in javascript...
One solution is that you should find the client id from the aspx page load function and return this client id into javascript function.

Then you can find the control by adding this client id before controlid.

I'll give you one example:

in the pageload

Page.RegisterStartupScript("Pageload","<script>Users.PageLoad('" + this.ClientID + "_');</script>");

in the java script

Users = { 
PageLoad: function (id) {
    ClientId = id;
  
},

Hope this may help you

javascript validation

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