ASP.net form getting JS error

Question

I have an ASP.NET form (C#) but which I click this button that should execute a JS method I get the error "Microsoft JScript runtime error: 'document.getElementById(...)' is null or not an object"

This is odd because it should work:

                <asp:LinkButton ID="btnDriverPopulate" runat="server" Text="" Height="55px" Width="172px" CssClass="btnMTO" 
                    OnClientClick="readLicense()" ToolTip="Check Driver" />

textbox code here

 <asp:TextBox ID="DriverLast" runat="server" Width="180px" Text='<%# Eval("Last") %>' ToolTip="Enter driver last name"></asp:TextBox>
                                    <cc:TextBoxValidator ID="valDriverLast" runat="server" AllowBlank="false" Display="dynamic" ControlToValidate="DriverLast" ValidationGroup="ValGrpDriver"
                                        CorrectFormat="Please enter in alphanumeric characters only." FieldName="Last Name" RegString="^[a-zA-Z0-9\s.,\-']+$" />

JS function readLicense that SHOULD set the textbox's value to "hi"

document.getElementById("DriverLast").value = "hi";

Darren · Accepted Answer · 2012-06-13 14:36:16Z

1

In the markup is there an input with the id DriverLast? ASP.NET may changed the ID of this control to it's container ID, i.e: _ctl_DriverLast. Therefore you could use the ClientId property.

Try:

document.getElementById(<%=DriverLast.ClientId %>.value = "Hi";

answered Jun 13, 2012 at 14:36

Darren

71.2k24 gold badges141 silver badges146 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Darren Over a year ago

Look in the markup, do you see an element with the ID DriverLast?

jrummell · Accepted Answer · 2012-06-13 14:34:24Z

0

The rendered client id isn't necessarily the same as the server control id. You can use the ClientIDMode property to change this behavior.

document.getElementById("<%= DriverLast.ClientID %>").value = "hi";

answered Jun 13, 2012 at 14:34

jrummell

43.2k18 gold badges116 silver badges179 bronze badges

2 Comments

jrummell Over a year ago

Can you verify that the id in your script matches the id of the html element?

Bulvak Over a year ago

I did that and you're right! the id seems to be different when I go to my html source, I pasted the html source textbox's ID and no error!

Collectives™ on Stack Overflow

ASP.net form getting JS error

2 Answers 2

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related