Validate textbox with RequiredFieldValidator only if CheckBox is unchecked

[Naunt]

Please kindly help. I want to validate textbox only if checkbox is unchecked, if checkbox is checked no need to validate textbox as require field. At where and when I have to attach and deattach RequireFieldValidator to textbox? Thanks and best regards.

[Not Active]

The ASAP.NET field validaators are run with JavaScript on the client first, then on the server if you have a Server meethod defined. Use some JavaScript to test when you click your submit button, or whatever method you are using to submit the form.

function ValidatePage()
{
return Page_Validate("VALIDATION GROUP NAME");
}

---

I know the language. I've read a book. - _Madmatt

[Lost User]

You can try using a CustomValidator[^].

[Naunt]

Thanks Mark Nischalke and Shameel I added a CustomValidator to the textbox and add ClientValidationFunction This is my solution to share with other people those who have problem as mine

*

ValidateEmptyText="True" also important here, if not control will not doing validation.

function CheckPorts(sender, args) {
var chk = document.getElementById('<%= CType(CreateUserWizardStep1.ContentTemplateContainer.FindControl("chkViewAll"), CheckBox).ClientID %>')
if (args.Value == "" && chk.checked == false) {
args.IsValid = false;
}
else {
args.IsValid = true;
}
}